I weigh 66kg, I modified a chinese ybr knock off into a cafe racer. Removed airbox for new sport carb and filter, blanked EGR valve and rerouted the crank breather, chopped standard can and replaced with akropovic slipon. Polished intake manifold. Had head ported and polished. Replaced seat and tank for lightweight cafe racer alternatives. Installed clipon drop bars and lowered front and back 2 inches. Put sport cg150 cdi in to replace origional. Use high power sport battery, iridium plug, Changed sprockets for better acceleration.....lots of other stuff too. It wasn't expensive as i do most of the work on my bikes myself, definately not impossible like matt makes out. Prabably not worth it to most people, but definately possible to increase a 125 4t power if you look past the usual 17 year old propaganda parts and actually tune the engine. It pulls like no 4t 125 i've ever ridden, so don't be put off if your hearts in it and you've got the cash.
After reading that long list what happened? Most of the stuff you did/had done made NO difference. For instance; Removed airbox Polished intake manifold Crapovich slip-on Lowering the bike 'Sports battery' whatever that is Iridium spark plug All of the above did nothing other than coat money. The rest just improved a shite engine slightly...
@@dirtygarageguy it took a lot of jetting and carb work to get it running sweet, low and mid range power is dramatically improved. Removing a standard restrictive airbox made to get a bike through emmision test and replacing it with sports alternatives does increase power, as does swapping the origional restrictive exhaust for a povich. Polishing the intake manifold and up jetting where appropriate also improves power. Lowering the bike was entirely asthetic and to give a more racey riding position. Changing the tank and seat and stripping all fairing also saved weight but tbh where asthetic changes more than anything. I can't say if the high preformance battery makes a difference but it was only 23 quid more than standard so who cares. I couldn't do the rest and not put an irridium plug in. The cliponss are just to make it prettier. Can't say that the 150cdi made a massive difference. The rear sprocket swap delivers far more available power the whole way through the entire rev range. I didn't do the head work myself but it was probably the most noticable difference in power. It revs off the dial now when it gets thrashed, it tops out at around 70 but i've changed the sprockets to keep acceleration not top speed. I've probably forgot a few things but thats the bulk of it and it goes like stink (for a 4t chinese 125). It's no hayabusa but a 125 never will be. Theres a lot of fun to be had making a little bike go faster just like making a big bike go faster matt. It dosen't have to be sensible or cost effective to be fun mate.
@@dirtygarageguy and everything you said just coated it in money cost less than £200. £30 carb, £15 air filter, £0 povich from a breaker in my shed, lowering costs nothing, all bikes need a battery but i'll admit a preformance battery may just be a gimmick....but for £23 extra noone cares. The iridium plug cost £9. The cafe racer seat cost £35+delivery and the tank cost £40, the 150cdi was £20 and the chain and sprockets were £30. So thats £200ish all in for the work i did myself, not a huge ammount imo to say i got the bike given. The head work cost £110. So for the price of a clapped out fizzy 50 i have a cafe racer custom that turns heads and has a bit of poke. Don't see how you consider this a waste.
"it took a lot of jetting and carb work to get it running sweet, low and mid range power is dramatically improved." - are you sure this isn't just switching the sprockets? Without a test how would you know anything? "Removing a standard restrictive airbox made to get a bike through emmision test" - That's not what airboxes are for... and you've probably made it worse. "I couldn't do the rest and not put an irridium plug in." - Why? You obviously don't know what iridium plugs are for... "The rear sprocket swap delivers far more available power the whole way through the entire rev range." - That is not true. "Theres a lot of fun to be had making a little bike go faster just like making a big bike go faster matt. It dosen't have to be sensible or cost effective to be fun mate." - LOL you make it sound like I was never young. What I'm saying in the video is is don't waste money changing a 125, because all you'll do is waste money. If you spent £50 then great. One other thing is all the things you did do that didn't work, what have you learned from that? Because it sounds like you learnt nothing and now believe that these changes work. I do have soem questions though. 1 - "lowering costs nothing" - by doing what? I know you probably lowered where the yokes mount on the shocks, but what about the rear? 2 - "The head work cost £110" - by doing what? "Don't see how you consider this a waste." - On a piece of shit chinese 125, I can see it's a total waste. Are you head bearings any good? Wheel bearings? Wiring, lights etc etc? You ride that bike and think it's fine, but do you have enough experience to know what a shite and what a good bike feels like?
@@dirtygarageguy rode the bike for weeks before deciding i was goin to fiddle with it, so yeah i'm pretty sure. The standard air box had the crank breather and the egr pipe leading back into it, so yeah it was getting dirty air and bieng suffocated. They do this to help get through emmision, aswell as to help with cold starts. Iridium plugs increase spark efficiency. The sprockets definately do, it used to read 80+ mph when i leathered it (my low body mass was probably a lot to do with that) but now tops at 70ish and gets off the line faster without the flat spots in the rev range. Yeah i lowered it 2 inches at the yoke and put shorter rear shocks on that i had from another build. I had the valves ground out and polished, and the clearences set properly. All the running gear is in good condition tbh, need to change the brake light for something more 'racey' that dosen't stick out of the back but thats about it. If a few hundred quid on a ybr knock off to make it look better, go better and sound better is too much then we must agree to disagree. My other bike is a 2t gpr 125 thats had a hell of a lot of work done to it (cba listing it here). I've ridden a blade 948, an sv 650, a cbr400rr, a cbr 150 import, a bandit 600 and too many 125's to list. So....yeah i know what a bike should feel like. As for the stuff that didn't work and i should of learned from......what exactly? Nothings set on fire or fallen off 😅 and i've been doing this a long time. (I assume not as long as you) Hope i didn't miss anything bud.
+Mateusz M DON'T listen to people that don't know. Yes they DO require a little bit of maintenance now and then, but the benefits are triple the power of standard 4stroke 125cc bikes. They are SO Simple to fix that I used to spend approx 1 hour per month on maintenance for the road. Yes my 2 stroke highly tuned Off Road race engine needed more but same with 4 strokes EVERY race/meeting you strip engine so it operates at peak power/reliability.
As long as my bike can keep up with traffic I'm happy 😂 been on backroads and passed loads of 125 scooters, and they're giving it everything they've got, and I'm just happily passing by 😂 I'm more than satisfied with that. Plus so many drivers are driving just below the speed limits where I am, so just the pure overtaking is more than enough to make me happy 😊if I want more speed I'll do my test and get a bigger bike 😂 all in due time
6 years late to this party. 48 years old now. Haven't ridden for 30 years. Just done CBT and brought a GN125. Does 50mph tops. You've saved me going down an unnecessary rabbit hole. A1 and A2 sounds like the best way to get more power 👍🏻 I think GN stands for Go Nowhere 😂 😂
@@Dwainpipe21 14 stone. Think carb needs tweaking. Been experimenting with mixture and needle clip with various different results. None good. Seems the last 10mm of throttle twist makes it hold back rather than accelerate in 3rd gear onwards. Done valve clearances. Have gone richer with the carb. Going to start looking at the leaner end now 👍🏻 Also has great compression.
@@adbadb17 could do a plug chop to see how it's running ? If it bogs down with a wide open throttle it sounds like it's running too rich? .....is the ignition breaking down at high rpm......prob not as it would do it in first or just cut out rather than hold back ? ......gearing correct? Cam timing correct? ...... probably is as it would show in all gears not just 3rd onwards. Standard air filter /box and exhaust?. Know how you feel as it's bloody annoying! .......set it alight and claim insurance? Lol no don't do that you will find it ..... eventually.
@@Dwainpipe21 plug looks a nice colour. Cone air filter, but I still have original. I believe the ignition timing to be electrical and non adjustable? Exhaust not standard, but not a performance one either. It's what it came with, but I had to make a bracket to fit to rear peg mount, as it didn't align, so def not standard. Diaphragm on carb is sweet. Carb all clean. Have a manual, so will set it back to factory settings with std airbox and see where we are at. Cheers for your help. Much appreciated 👍🏻 😎
Best thing I've found is learning how to corner quickly, on the back roads I'm riding with mates on a 125 the 5-10 mph more some bikes have top speed doesn't make a difference (unless you have a 2 stroke). Although most Chinese bikes will get left behind as they top out at around 50-65 rather than 80 on a big brand bike
Thanks for your videos. They are educational and fun at the same time =). First thing i thought about when you started chopping the painted bike on the whiteboard, is that if you alter the bike too much (like removed headlight and such), the drag increases. So in your example, I believe that the extra HP (to weight) will be eaten up by the drag when trying to go faster. My guess is that it will not go any faster because of that. Drag increases squarely with speed if I remember correctly. So my best bet to get a 125 go faster, is to work with aerodynamics instead of cutting weight off of it. Weight is only an issue during acceleration. A car does not need much horsepower to go at about 90 km/h, even though they are very heavy. But they are way more aerodynamic than motorcycles though. Thanks for your vids =).
Well I'm around 84kgs, then you've got to add the weight of all your protective gear too. Probably about 90kgs with gear on. Add that to 146kg bike, so the total weight would be 236kgs for a 125 and with myself onboard.
Hey mate you've shed some lights of wisdom on me 🙂 I'm 110kg did a few mods to my Yamaha y110 2 stroke and it just gained a mere 7kmh more top speed lol well your right these small bikes really work for those
Thank you, that makes perfect sense. Changing sprocket sizes in favour of top speed won't help then? I guess any small gain in top speed would be lost at the first hill encountered, because there's no increase in power.
Yeah if I was pottering around town and was fairly light (wouldn't work for my fat arse) I'd be willing to loose a bit of pull off for that bit of top end
I think you can get a decent amount of power from a 2 stroke 125 such as KTM or TM but as you said, you are going to have to do a lot more maintenance.
Well I weigh 55kg soooo it might go maybe 150kmh stock but if I put a performance exhaust, performance air filter, and maybe performance headers, I presume it may go 160kmh, it would basicly be as fast a 2 stroke, I am not sure if I’m right though
I loved my 125, the slow bastard. Well, it'd do 65mph and that was all I needed for going to work and back and popping to see mates or going for rides.
Thats why i had a rs125 2 stroke when i was 17, that was around 30ish bhp, but the best thing i did was get my licence done and move up to a 600, totally different experience and i still love it now
Good video & completely true. You can only get so much power out of a small engine so riders are better off saving their money till they can get a bigger bike if they want to go faster. In the USA if you wanted a fast 250 you had to get a 250 ninja as the other street legal 250s were either enduro's or cruisers & alot of those bikes had no way to hop up their speed, except for changing a sprocket & bigger main jet which'd get you another 4-7mph. Any other speed mods are too expensive to be feasable unless you are racing in a league. Save your money & put it into a bike 500cc or larger & you'll be happier w/it & hold onto the bike longer as you get older.
I have been down this road. Now I am in my 30s and realised what you said through my experience. When I see young people some even old modifying a 100cc or 150cc I am like "why bother, just upgrade".
I was going to upgrade the 125cc starter bike I'm buying for insurance reasons once I can insure one of my bigger bikes for reasonable rates just for shits and giggles. Naked bike it. Off Roadish tires. Bore kit maybe stroke kit it I can find one. Tiny turbo meant for snow mobiles and dirt bikes. And just sorta abuse the thing plus teach people how to ride on it. But probably not even going to bother cost less just to sell it and buy a ktm 390 or something similar.
50cc mopeds are fun, if you tune them a little they can go pretty fast haha. 60 mph maybe does not sound like much but when you sit on a bicycle frame held together with zipties its different (y)
The life of the engine is greatly reduced it just brings the engine rebuild closer. The piston rings only last so long even with the best maintenance and 2 stroke oil
Stiff suspension, good sprocket ratio, tightened chain, good oil, aftermarket air filter, exhaust, fueling, cdi also changing the tyres is a big help however all this cost's more than what it's worth you may as well swap the engine for a 250 lump
back in the 80S on a ypvs raising the exhaust port by abot 10-15 mm made a big driftnets if i remember me Yamaha rdlc 125 did 85 to 90 isss when it wos standers and think around the 110 open so i wood recomend a good porting job on a t2 and gas flowing a t4 but is harder to live whit ass below the power band is shit so you have to keep in the power band ore drop gears to get it gowning
Good overview for sure. Bottom line, Speed=Money, you want to go faster, your either going to have to open your wallet wide, but regardless you'll be opening it often as reliability will suffer because its so far past the original design target. You mentioned the scooter guys with the two strokes, as you said they increase displacement and radically change the port timing where the powerband is abrupt and unless its ridden to the limits has no power and typically will have no bottom end power so at less than 10/10's its not fun to deal with. I've been on a few runs with these guys and the fastest and most modified bikes seize up rather often. Typically as soon as it cools they're able to continue but it does cause damage every time it happens.. I know this might be hotly debated, but it doesn't take research to see those that push an engine past its original power are frequently replacing something, the factory knows this, its probably why they get the design to a compromise level to get it past a reasonable warranty period. Just an opinion for sure.
" I know this might be hotly debated, but it doesn't take research to see those that push an engine past its original power are frequently replacing something" I smeel another video coming, I love hot debates lol - cheers for the comment - matt
This is much more relatable when you live in south east asia. Like i do. But 150cc does go up to 62mph(bad engine condition tho). And my bike and me weighs a total of about 170kg-ish (asian. Im relatively small and light). But boi when 98% of the population is on less than 250cc bikes. We push these engines so far, and still use it daily. Like a 125cc engine bored up to 180cc and big valves, aggressive cams, big carbs. Suddenly your 9hp is now 22hp, just like you say. But what is not 'true' from what you say is their reliability. Guys that goes up in bore usually also uses forged parts in the process too. So reliability isn't compromised as much as you might think. Sure it still will shorten the lifespan, but the whole bike itself usually goes too old first before the engine even breaks down, so not too relevant. And i personally am riding a bored 150cc bike (from a 135cc) daily :)
Going from 135 to 150 really isn't a huge increase or worth bothering with is it? That's only an 11% increase, factoring in the cost, work etc..........
The Workshop yes if my intention was just to bore up. That is way to small. But when i did it, it was because the conrod was shot, and the cylinder block was scored to hell as an effect. So i needed to change the conrod, piston, and cyl block anyway. Going up to 150cc was like as extra $10 to the already big list of parts since i'm just using a part from another 150cc engine that was from the same engine family. So it was still a plug and play upgrade
susah bilang. mx ane skarang udah sampe 106000 km. ane tangan ke-3 dari sodara smua, tapi kondisi pas ane dapet udah kurang sehat, dan sampe skarang belom full sehat. jadi gak bisa bandingin sama mx standar pabrik enak yang mana.
To make his 125cc bike faster my friend made his own sprockets and put a large one on the engines side and a small one on the wheels side. It reduced the torque and increased acceleration times, but upped the speed to 100mph
Im 15 and ive been considering buying an ktm exc 125 cc, and turning it into an supermoto. i already own an yamaha mt 125 (2018, 2020 and 2021 are hella ugly). where i live riding fast is a lot more about skill than top speed, i for the most part drive faster than my older friends with bigger bikes, but if the curves are far apart or your able to keep a high speed through them they disaper infront of me. The exc will have an higher top speed and much faster aceleration. ive seen videos of modified exc 125s gap 300cc bikes. is this going to be worth the hassle in performance. Money wise i will probably get more back when selling than i used on the bike so thats no problem.
Sorry for noob question but I saw a video where they said if you care only about acceleration and not top speed put in a bigger rear sprocket or a smaller front socket. Is this really true?
most of it depends on the bike, if its a rc 125 of yzfr 125, the engine has the potential for more power but its restricted to make it learner legal, put a remapping chip in and your done, but bikes like a ybr just don't have the potential for more power in the engines
Имам 125cc 4 stoke скутер :) Какво е по-добър мод от по-висока скорост? Сега в спускане имам 134 км / ч = 83 мили! Най-голямата струя е добри възможности?
What about if I took a cheap Chinese bike and put in a aprilia rs4 engine n changed the sprocket the back tyre and a big bore kit and wider tubing aswell as replacing some of the steel parts for carbon fiber
What if you got a 125cc 2 stroke? I heard of a guy that had a aprillia rs 125, he just pulled a restrictor plate from the exhuast system, and the bike then ran so much better..
Matt I noticed my glr125 did 65mph after 8000 rpm, which is where honda claimed was peak power, I didn't understand why top speed was after peak power. I upped the gearing and it'll do 70-75 now.
Be good if you covered the 2 stroke side abit more as it would add a lot more depth to the explanation... but the simple answer is most 2 stroke 125s aren't learner legal once derestricted or modded. But there is a lot of interesting stuff to cover, squish, ignition timing, carbs, reeds, exhausts etc. I built a rs 125 with lots of engine goodies and would like to think it made the 33hp everyone bangs on about... vhm head etc etc etc
Will be doing, I have alot to do but a lot of time in the future. One of the next projects coming up is the AM6 rebuild where I can use that engine to go through the things you've just mentioned. I do have video from 2 years back that does cover alot of this. Just look on my video tab on my channel. - matt
Kids! If you take your standard sprocket set and replace it with racing sprockets with less teeth up front. You WILL notice a dramatic difference in performance and acceleration. Cheap enough upgrade too. Or of corse, get a 2-stroke. You'll be striping it down every week but you can go as fast as you want.
I've done 135 kph (81 mph) on flat just with a k&n filter mod, full stock, it cant go above 135 not even in 89° downhill xd so its quite good for a 125 i guess
The cooling problem when a stock engine is pushed for maximum horse power is rarely addressed in my opinion. The heat takes a horrible toll on little engines.
I have a honda bike 125cc and its 98kg only in stock condition... I have use some tweaks like i removed the mudgards headlights etc but it can go only 120kmph which is not enough its 11.6hp what could be the issue???
I'm no mechanic and I'm relatively new to the motorbike scene. I'm not trying to zoop up my 125cc for 1-3 hp gains but really just a random question. If anyone know, as there seems to be alot of people on this video who knows what they're talking about. (I'm 33 BTW and o ly riding a 125cc on a cbt to get used to bikes before I do my direct access and get a big boy bike) but that aside my question is. Why will my bike some days sit comfortably at 65mph on a flat and other days struggle to get past 55mph? I know environment can change ie wind and inclines etc. But throughout the summer on windless days it was like the bike had a mind of its own.. Is there anything I could be doing to stop it getting to its full potential or is it purely cos its a 125cc and it decides when it wants to go faster lol? I've been had 78mph out of it downhill wind behind me lol but I'd just be happy if it sat at a constant 60mph on a flat
@@dirtygarageguy ohhhh that makes sense thank you for not being condescending etc lol but if I don't know I like to ask we all knew nothing at one point.
This is probably gunna come off sarcastic but this is a genuine question, the Honda CRF125 is their 4 stroke single air cooled off roader, and depending where you look the specs vary from 20-24 BHP, which is vastly better than all over 4 stroke 125s so what is in the engine that makes it so much more powerful?
Great question - 1) Engines CBR125 (street bike) Bore x stroke = 58 x 47.2mm Oversquare CRF125 (offroad bike) Bore x stroke = 52.4mm x 57.9mm Undersquare The CRF has a more torque engine - great for low down aceleration. 2) Weight CBR125 = 137 Kgs* CRF125 = 87 Kgs* (*neither state dry of wet weight) 40+kgs is shit loads, that's nearly 50% of the weight of the CRF. This helps with acelerarion 3) Gearing CBR125 = 6 speed CRF125 = 4 speed This demonstrates that the CRF is designed to acelerate fast that is the main focus. As the CBR is designed more for top speed than aceleration, due to the fact that its so heavy means that they have little choice. The summary is that the CRF is eating into its reliability hence the 6 month warrenty vs the CBR's 2 years with unlimited miles. The CRF engine is a torquier engine and like I always say - torque is king.
The Workshop so if the engine is geared for torque not top end speed, what would the top speed look like let's say if you did an engine swap? Hypothetically of course
If the engine produces more power then a higher top speed, but the CRF is designed to give up most of its power early on, so your top speed would be higher, but you're oribably gonna run out of road before you reach it. Secondly the engine will go pop sooner, higher torque means higher forces
How could an aircooled 125cc ever make double the horsepower of a watercooled 125cc i know speedway bikes are aircooled and make big power but do they almost overheat in just a few laps
I bet you a dollar this video attracted thousands of spotty teens keen to get their wee put put puts to go faster and they where disappointed lol... Now did that Brock the Cock bloke not manage to gain another horse by grinding the fuck oot the pads.. lol .. Think i'm on video thousand out of thousands Workshop videos.. Great channel.. :)
I had a Suzuki rgr 125 gamma (two stroke) years ago and that was factory deresticted.. no bore kit, no sprocket or exhaust change. That thing would do 112mph.. it flew! I was 10 and a half stone. Dont make bikes like that anymore.. it never broke down either and I had it two years.
No they dont last 5 minutes. My mate has a 125 rotax and to keep that 30hp he need to rebuild the bottom end every 30 hours but rotax say it only needs to be done every 50 hours and the top end needs to be done every 15 hours. This is to keep 100% of the power to competitive usage. For an Engine used for weekend racing that sort of maintenance isn't that bad.
No I'm not dumb im just defending my favourite 2 stroke 125 engines. Plus 125 4 stroke engines are crap i don't even know why people even decided to make them. 2 stroke engines are far Superior in these smaller packages.
While it'd only work temporarily it might be pretty easy to use a 12 Volt cheap ass Amazon electric turbo to add a few extra ponies for passing. Would be fun for certain situations. Probably not entirely worth it but bore and stroke kit. Turbo or super if you can set one up small enough. And then just work on tuning flow and effiency as reduced or increasing pressure and other shit can affect hp a bit. Potentially add an extra spark plug for better burn. Reduce the parasitic losses. Better intake and exhaust. Potentially figure out a cheap way to DIY a ram air set up. Then like you said reduce weight. Play with gearing. Throw a little nos.
Got myself a 2007 yamaha xt125 R, 10hp, "naked" of course it being an offroad oriented bike. I was able to go 110 kmh in the highway with some juice still in there. Thought through it and found myself an wc top plastic cover, cut it down, made some mounts in the front fairing and woo now she does 120kmh, as a note, i test my top speed in the same highway straight, a level straight with not much wind. Aerodynamics when no ponnies will do you a lot guys.
Is a 4 stroke 125 going to have a higher output that two stoke 125? I would assume a two stoke burns twice the fuel than a 4 stroke giving it a more constant feed of power?
Hi matt my names will your vids are very good I have been enjoying watching them for a month or too now. very funny when you start ripping into people who think there clever than the manufacture " hard run in lol" these people honestly just do what manufacture says there not trying to catch you out there just looking after there special engines
well how did 125 sportspikes in early 2000s make 53 or so horsepower like the aprilia rs 125 but now they all are pushing max 15 hp i wonder how you can make the engine produce the same kind of power that engines used to.
Here in finland when you are 16 you can drive 125cc and i think that not most of 16 years olds doesn't weight 100kg so if they weight about 65-80kg so how fast that will go ?
there are loads of mods to make a BIG difference especially if your bike is released in country where they don't have the same restrictions , a few hp on a bike that has 10hp will feel like a new bike open up the exhaust open up the air flow increase the jet size or add a bigger carb increase the bore if for racing loose weight
"open up the exhaust, open up the air flow " makes fuck all difference. The direction of the wind, or how fat you are. Meaningless. "increase the jet size or add a bigger carb" - my favourite one. Try it - it doesn't work. "increase the bore if for racing" - then that's not a 125 is it??
Want a decent learner legal bike, DT125's are still the best option. Cracking little bikes. You'll still need a bus pass though because most of time they'll be in bits in the back yard. But at least you learn how to stick a new piston in and learn more about your machine.
The cagiva motto does a owner had a one that would push a 170kmh on the clock wich is like 108 mph and I only changed the jetting and exhaust thing was reliable and looked good I don’t care what anybody says the cagiva or the aprillia rs are two fastest 125’s of all time
how to:make you 125 faster make it road legal and change the engine :D (and you are set) buy a big bore kit change the sprocets change the air filter and thats pretty much all the mods you can do to make it faster
In Finland you can ride A1 class bike (125 or less cc and 11kw (about 15 horsepower)) at an age of 16. when ur 18, you van have as many ccs as you want but only 35kw and it has to be restricted from max 77kw's. at 21 you dont have any limitations.. weird isn't it....
Weight reduction wont change top speed at all except for a tiny tiny bit from reduced tire friction. Top speed is purely a matter of drag vs horsepower.
@@dirtygarageguy yes, worth buying 1 at that price, since the 125R came out, a lot of worry 300 contenders like rhe cbr300r and yamaha r3 are available but at a totally higher price plane, thoughts? This is for starter/learner 🚲 bike
top speed is defined by wind resistance , the loss of weight will just make it accelerate a little faster .. then wind resistance becomes the brick wall , you need more "real" power to make it go faster.
Memories... Damn does anybody even remember there was "legal" 125cc spiting out >30HP that you could buy and run without messing around. Well they lasted 6 months to 1 year before the engine needed serious intervention and the power band was narrower than the waist of a bulimic. LOL :-) But they where on the market side by side with 125cc 4 stroke for anybody who really wanted to ride long and cheap. I still recall 50cc with a boost, usually 75cc and a FEW more goodies overtaking on the road with me seating comfortably at 130km/h and they just passed, screaming like crazy. :-)
Peter Lindström - That's it. :-) Along with those gorgeous Italians like Cagiva's, Aprilia's, Gilera's, etc...Real pocket rockets for anyone to ride. The workhorses of the real world like Honda CG 125, CUB and alike's shared the same roads with 10/11hp engines designed 20/30 years earlier. When the latest option is what we can get today makes us wonder about "evolution" written out by the stroke of a government pen. Nowadays it's emissions, driver's license restrictions and a lot more. :-(
I had a brand new Aprilia Rs 125 when I was a lad 2 stroke......within the first week of having it took it down to my local aprilia dealer who at the time i knew to get it de-restricted..he took it in the back snipped a wire in the tail unit told me to be carefull on it and steer clear of the old bill. Jesus Christ it went like a lunatic ....a proper angry little bike. After speaking to a lad who club raced the same bike he said they were 33bhp....I remember racing a bloke on a 600 bandit down a long straight and he couldn't get away I was laughing my nuts off....Aww them were the days 17 yrs old riding round like headcase thinking I was a grand prix rider when really I was just a snot nosed little shit on a 125. Long time ago now I'm nearly 40 great memories though.
Although I agree with everything said in the video if I was looking to buy a 125 and wanted to improve it as best I could I would buy the older model CBR because it's smaller in size, relatively cheap, lighter than the r125 and narrower tyre sizes so less friction and wind resistance. It also produces good power to start with and an easy upgrade to 150cc as there is also a 150cc model in other markets.The r125 is physically much bigger so although it makes slightly more power there is much more motorcycle to push through the air.chinese bikes are fine nowadays and there is a wide choice at very good prices plus good spares back up but the engines make only 12bhp at best with many only 10 ish bhp although there are many big bore kits cheaply available . The CBR just seems the best all round bike in terms of quality, power, weight and upgradeability in my opinion so that would be my choice if I was looking at having the fastest 4t 125 ( with an obviously illegal cc upgrade!) At a reasonable cost .
Cheapest way really. Put a bigger cc engine in. Or have it tuned at great cost (over a bigger cc engine) or spend loadsamoney on air filters +exhausts to have no noticeable gain. Best thing tune the speedo. We did 90+ mph (Yeah we all - sensible knowledgable people know 72mph was absolute max on a testtrack) in the "olden days" in 850cc Mini´s (std engine ¨cose the speedo reading was SHIT, but we wuz wankers and wanted to believe it. Same as people today. Innit bro?
@TJ's Garage I imagine it reached that speed going down the mountain, and probably so did I to think about it. Not on road it maxed at yeah about 70, but that's only when it was up and running. A very rare thing indeed 👍
Best you can do is change front and rear sprockets to around 20% shorter gearing, have to work hard for top speed but you can rip around town and power wheelie in 1st. Should hit 60mph at peak power in top gear still which is is about all you can hope for against wind or slight uphills, plenty of speed for anything below a dual carriageway. Could maybe hold 65 reliably with exhaust etc but easily 6* the price of sprockets.
Raising the idle to around 1.5 to 2* the stock setting will also help get of the line and get rid of jerk and stall on overrun in combination with the previous.
I agree with the principals but your maths isn’t right at all. Air resistance isn’t linear. A 40bhp bike will do 120mph if you’re lucky. By your maths it would do 240mph.
Hi. I watched the video and read all the comments. In my opinion it all got a bit out of hand also a bit childish. I have a 125cc motorbike ( not brand new but nearly ) and when i first went out on it i thought that the stock exhaust was somehow restricting it, the sound and feel when in high revs felt like it couldn't get rid of the exhaust waste quick enough. So I bought a full brand new aftermarket exhaust for it, fitted it and took the bike out i noticed straight away in high revs the bike felt alot better and felt like it was running to its full potential. I did think it increased my speed through the gear range but very slightly only. So the question is do you think getting this new exhaust was a waste of money and time. The exhaust cost £220 ish.
1) you didn't feel the exhaust being restricted. No one on earth to "feel" that because there's nothing to feel. 2) 125 bikes go from slow to not so slow. The fact that's they have 125cc is literally why this happens. So do I think £220 is worth it? For me, no. I had a 125. I wasted that kind of money on it. And as you can see, you know how I felt about that. You can spend your money on what you want, but what I said about saving that money and spending it on a bigger bike in the future is a fact. Saving that money will make it better for you in the future where it counts. For example. Spending £200 on brake pads is common, and when you rapidly slow down from 100 to 30mph, you notice. My old 125 couldn't do 100 mph, never mind slow down from that speed.
@@dirtygarageguy Why save money to buy a bigger bike, i chose the 125cc i am not getting a bigger bike. Bigger is not always better. Also i could feel that the exhaust was restricted. You do not have to touch to feel. Because i FEEL like you are been deliberately confrontational.
Imo a 125 can get you moving , I beleive with another cylinder say 250cc twin would give best of both worlds not too heavy a bit more go but will yhe same frame work with a little extra breaking capacity ...and as you said is it worth the work ..
My friend builds race scooters and recently he built a C group (stock) one, that produced 16hp at the wheel. Things like tighter tolerances, drilled out lightweight / DLC coated parts, heat isolation for the intake, the magneto rotor is so lightened out that it isn't even magnetic anymore lol. It was amazing watching him build it, and it was amazing to ride, you'd never believe it's a stock 125cc with stock (polished ports) cyl.head. HOWEVER it costs a fucking fortune! You can buy a good motorcycle for that. So for people who want a faster 125, unless you're racing, just get a simple big bore kit that you can install yourself and don't waste anymore money ;)
Cg125 does not go any speed easily maybe 35mph it's even a pushrod engine until the very late model even then i'm not sure they don't rev for shit nothing with pushrods ever does
what i dont get is why you cant produce more power out of the engine because if you look on an 600cc sportbikes with 110hp (for example) and divide the cc with 4 (4 cylinders) you get 150cc for every cylinder.then divide the 110hp with 4 (again 4 cylinders) you get 27,5 hp for each cylinder.so why you cannot make our 125cc bike easy over 20hp?of course not near 27hp
I weigh 66kg, I modified a chinese ybr knock off into a cafe racer. Removed airbox for new sport carb and filter, blanked EGR valve and rerouted the crank breather, chopped standard can and replaced with akropovic slipon. Polished intake manifold. Had head ported and polished. Replaced seat and tank for lightweight cafe racer alternatives. Installed clipon drop bars and lowered front and back 2 inches. Put sport cg150 cdi in to replace origional. Use high power sport battery, iridium plug, Changed sprockets for better acceleration.....lots of other stuff too. It wasn't expensive as i do most of the work on my bikes myself, definately not impossible like matt makes out. Prabably not worth it to most people, but definately possible to increase a 125 4t power if you look past the usual 17 year old propaganda parts and actually tune the engine. It pulls like no 4t 125 i've ever ridden, so don't be put off if your hearts in it and you've got the cash.
After reading that long list what happened?
Most of the stuff you did/had done made NO difference. For instance;
Removed airbox
Polished intake manifold
Crapovich slip-on
Lowering the bike
'Sports battery' whatever that is
Iridium spark plug
All of the above did nothing other than coat money. The rest just improved a shite engine slightly...
@@dirtygarageguy it took a lot of jetting and carb work to get it running sweet, low and mid range power is dramatically improved. Removing a standard restrictive airbox made to get a bike through emmision test and replacing it with sports alternatives does increase power, as does swapping the origional restrictive exhaust for a povich. Polishing the intake manifold and up jetting where appropriate also improves power. Lowering the bike was entirely asthetic and to give a more racey riding position. Changing the tank and seat and stripping all fairing also saved weight but tbh where asthetic changes more than anything. I can't say if the high preformance battery makes a difference but it was only 23 quid more than standard so who cares. I couldn't do the rest and not put an irridium plug in. The cliponss are just to make it prettier. Can't say that the 150cdi made a massive difference. The rear sprocket swap delivers far more available power the whole way through the entire rev range.
I didn't do the head work myself but it was probably the most noticable difference in power. It revs off the dial now when it gets thrashed, it tops out at around 70 but i've changed the sprockets to keep acceleration not top speed. I've probably forgot a few things but thats the bulk of it and it goes like stink (for a 4t chinese 125). It's no hayabusa but a 125 never will be. Theres a lot of fun to be had making a little bike go faster just like making a big bike go faster matt. It dosen't have to be sensible or cost effective to be fun mate.
@@dirtygarageguy and everything you said just coated it in money cost less than £200. £30 carb, £15 air filter, £0 povich from a breaker in my shed, lowering costs nothing, all bikes need a battery but i'll admit a preformance battery may just be a gimmick....but for £23 extra noone cares. The iridium plug cost £9. The cafe racer seat cost £35+delivery and the tank cost £40, the 150cdi was £20 and the chain and sprockets were £30. So thats £200ish all in for the work i did myself, not a huge ammount imo to say i got the bike given.
The head work cost £110. So for the price of a clapped out fizzy 50 i have a cafe racer custom that turns heads and has a bit of poke. Don't see how you consider this a waste.
"it took a lot of jetting and carb work to get it running sweet, low and mid range power is dramatically improved."
- are you sure this isn't just switching the sprockets? Without a test how would you know anything?
"Removing a standard restrictive airbox made to get a bike through emmision test"
- That's not what airboxes are for... and you've probably made it worse.
"I couldn't do the rest and not put an irridium plug in."
- Why? You obviously don't know what iridium plugs are for...
"The rear sprocket swap delivers far more available power the whole way through the entire rev range."
- That is not true.
"Theres a lot of fun to be had making a little bike go faster just like making a big bike go faster matt. It dosen't have to be sensible or cost effective to be fun mate."
- LOL you make it sound like I was never young. What I'm saying in the video is is don't waste money changing a 125, because all you'll do is waste money. If you spent £50 then great. One other thing is all the things you did do that didn't work, what have you learned from that? Because it sounds like you learnt nothing and now believe that these changes work.
I do have soem questions though.
1 - "lowering costs nothing" - by doing what? I know you probably lowered where the yokes mount on the shocks, but what about the rear?
2 - "The head work cost £110" - by doing what?
"Don't see how you consider this a waste."
- On a piece of shit chinese 125, I can see it's a total waste. Are you head bearings any good? Wheel bearings? Wiring, lights etc etc? You ride that bike and think it's fine, but do you have enough experience to know what a shite and what a good bike feels like?
@@dirtygarageguy rode the bike for weeks before deciding i was goin to fiddle with it, so yeah i'm pretty sure.
The standard air box had the crank breather and the egr pipe leading back into it, so yeah it was getting dirty air and bieng suffocated. They do this to help get through emmision, aswell as to help with cold starts.
Iridium plugs increase spark efficiency.
The sprockets definately do, it used to read 80+ mph when i leathered it (my low body mass was probably a lot to do with that) but now tops at 70ish and gets off the line faster without the flat spots in the rev range.
Yeah i lowered it 2 inches at the yoke and put shorter rear shocks on that i had from another build.
I had the valves ground out and polished, and the clearences set properly.
All the running gear is in good condition tbh, need to change the brake light for something more 'racey' that dosen't stick out of the back but thats about it.
If a few hundred quid on a ybr knock off to make it look better, go better and sound better is too much then we must agree to disagree.
My other bike is a 2t gpr 125 thats had a hell of a lot of work done to it (cba listing it here).
I've ridden a blade 948, an sv 650, a cbr400rr, a cbr 150 import, a bandit 600 and too many 125's to list. So....yeah i know what a bike should feel like.
As for the stuff that didn't work and i should of learned from......what exactly? Nothings set on fire or fallen off 😅 and i've been doing this a long time. (I assume not as long as you)
Hope i didn't miss anything bud.
And I'm proud to be an American where at 16 I can buy a Busa and ram myself into the back of a car at 180 miles an hour... Freedom!
LostAI117 fucking do it the u
LostAI117 actually 17
lmfao o m days thats funny man.
you have donald trump as president...not so free anymore huh?
im high on helium were as free as the fucking eagles that soar this land you liberal bitch
To go faster on a 125 bike, find a big hill, and hopefully have a back wind. Use gravity boost!
Yep, gravity is the way forward.
Charlie Smythe Technically it's the way downwards
PJ and the Craxfords Funny
stick a tuned up 125 cc 2 stroke engine in ti
but your maximum rpm still the same
I shed 50 lbs, 1/4 of my weight, and no speed gain. Time for a turbo busa yammie.
Let's be honest, you just buy a 2 stroke...
everyone has told me they need much more maintenance. I just wanna ride man
Mateusz M 2-strokes will last for long if you drive them correctly
Get fed up using all that 2 stroke oil, and always having to be in the powerband to make progress
+Mateusz M DON'T listen to people that don't know. Yes they DO require a little bit of maintenance now and then, but the benefits are triple the power of standard 4stroke 125cc bikes. They are SO Simple to fix that I used to spend approx 1 hour per month on maintenance for the road. Yes my 2 stroke highly tuned Off Road race engine needed more but same with 4 strokes EVERY race/meeting you strip engine so it operates at peak power/reliability.
But if you wanna go to school or something 2stroke is a bad choice. You will smell like you are working at a construction. Smoky af
I appreciate the fact that you leave your bloopers in sometimes .never trust a man that can't make fun of them self
As long as my bike can keep up with traffic I'm happy 😂 been on backroads and passed loads of 125 scooters, and they're giving it everything they've got, and I'm just happily passing by 😂 I'm more than satisfied with that. Plus so many drivers are driving just below the speed limits where I am, so just the pure overtaking is more than enough to make me happy 😊if I want more speed I'll do my test and get a bigger bike 😂 all in due time
Very good video Matt. Thanks for putting the time in .
Well explained Matt. Clear, concise, and makes perfect sense! Thank You 👍
no worries mate
I feel bad for Isaac's bike. There's your solar mass.
You nailed it mate. Thumbs up!
6 years late to this party. 48 years old now. Haven't ridden for 30 years. Just done CBT and brought a GN125. Does 50mph tops. You've saved me going down an unnecessary rabbit hole. A1 and A2 sounds like the best way to get more power 👍🏻 I think GN stands for Go Nowhere 😂 😂
If your gn only does 50 either you need to stop eating chips or it's broken.
@@Dwainpipe21 14 stone. Think carb needs tweaking. Been experimenting with mixture and needle clip with various different results. None good. Seems the last 10mm of throttle twist makes it hold back rather than accelerate in 3rd gear onwards. Done valve clearances. Have gone richer with the carb. Going to start looking at the leaner end now 👍🏻 Also has great compression.
@@adbadb17 could do a plug chop to see how it's running ? If it bogs down with a wide open throttle it sounds like it's running too rich? .....is the ignition breaking down at high rpm......prob not as it would do it in first or just cut out rather than hold back ? ......gearing correct? Cam timing correct? ...... probably is as it would show in all gears not just 3rd onwards. Standard air filter /box and exhaust?. Know how you feel as it's bloody annoying! .......set it alight and claim insurance? Lol no don't do that you will find it ..... eventually.
@@Dwainpipe21 plug looks a nice colour. Cone air filter, but I still have original. I believe the ignition timing to be electrical and non adjustable? Exhaust not standard, but not a performance one either. It's what it came with, but I had to make a bracket to fit to rear peg mount, as it didn't align, so def not standard. Diaphragm on carb is sweet. Carb all clean. Have a manual, so will set it back to factory settings with std airbox and see where we are at. Cheers for your help. Much appreciated 👍🏻 😎
Best thing I've found is learning how to corner quickly, on the back roads I'm riding with mates on a 125 the 5-10 mph more some bikes have top speed doesn't make a difference (unless you have a 2 stroke). Although most Chinese bikes will get left behind as they top out at around 50-65 rather than 80 on a big brand bike
Very true
Thank you for making these videos by the way, very informative :)
No worries mate - thanks for commenting
Big brand 125s don’t do 80mph. A Honda CBR125 will only go 70 and that’s a lot of throttle. Plus it’s a sports bike, one of the faster 125s available.
@@Joelhetherington yzf r125 mine does 89-92
Thanks for your videos. They are educational and fun at the same time =).
First thing i thought about when you started chopping the painted bike on the whiteboard, is that if you alter the bike too much (like removed headlight and such), the drag increases.
So in your example, I believe that the extra HP (to weight) will be eaten up by the drag when trying to go faster. My guess is that it will not go any faster because of that. Drag increases squarely with speed if I remember correctly. So my best bet to get a 125 go faster, is to work with aerodynamics instead of cutting weight off of it.
Weight is only an issue during acceleration.
A car does not need much horsepower to go at about 90 km/h, even though they are very heavy. But they are way more aerodynamic than motorcycles though.
Thanks for your vids =).
Wonder how quick my yz will go if I lost a bita weight, I'm 6ft, 200+lbs and got 82 on flat road wit a slight headwind
Bigger cylinder, but yes you do compromise on reliability, that’s my experience, but the more power the better! Thanks for the video.
This is where my size is an advantage I weigh 56kg (I’m 5’1”)
You've got nothing on me boy. I'm 5'2" and just 43Kg. Get on my level son XD
The Q anorexic 101
@cheese bag same lmao, give or take a couple lbs
Well I'm around 84kgs, then you've got to add the weight of all your protective gear too. Probably about 90kgs with gear on. Add that to 146kg bike, so the total weight would be 236kgs for a 125 and with myself onboard.
Hey mate you've shed some lights of wisdom on me 🙂 I'm 110kg did a few mods to my Yamaha y110 2 stroke and it just gained a mere 7kmh more top speed lol well your right these small bikes really work for those
Thank you, that makes perfect sense. Changing sprocket sizes in favour of top speed won't help then? I guess any small gain in top speed would be lost at the first hill encountered, because there's no increase in power.
Just like you say, you can sacrifice acceleration for top speed but that's about it. - thanks for the comment - matt
The Workshop if you live in a fairly flat place it's a sacrifice worth making
Really?
Yeah if I was pottering around town and was fairly light (wouldn't work for my fat arse) I'd be willing to loose a bit of pull off for that bit of top end
At the end of the day, its your bike and your money, each to their own as they say - matt
I think you can get a decent amount of power from a 2 stroke 125 such as KTM or TM but as you said, you are going to have to do a lot more maintenance.
Well I weigh 55kg soooo it might go maybe 150kmh stock but if I put a performance exhaust, performance air filter, and maybe performance headers, I presume it may go 160kmh, it would basicly be as fast a 2 stroke, I am not sure if I’m right though
I loved my 125, the slow bastard. Well, it'd do 65mph and that was all I needed for going to work and back and popping to see mates or going for rides.
Thats why i had a rs125 2 stroke when i was 17, that was around 30ish bhp, but the best thing i did was get my licence done and move up to a 600, totally different experience and i still love it now
Good video & completely true. You can only get so much power out of a small engine so riders are better off saving their money till they can get a bigger bike if they want to go faster. In the USA if you wanted a fast 250 you had to get a 250 ninja as the other street legal 250s were either enduro's or cruisers & alot of those bikes had no way to hop up their speed, except for changing a sprocket & bigger main jet which'd get you another 4-7mph. Any other speed mods are too expensive to be feasable unless you are racing in a league. Save your money & put it into a bike 500cc or larger & you'll be happier w/it & hold onto the bike longer as you get older.
I have been down this road. Now I am in my 30s and realised what you said through my experience. When I see young people some even old modifying a 100cc or 150cc I am like "why bother, just upgrade".
I was going to upgrade the 125cc starter bike I'm buying for insurance reasons once I can insure one of my bigger bikes for reasonable rates just for shits and giggles.
Naked bike it. Off Roadish tires. Bore kit maybe stroke kit it I can find one. Tiny turbo meant for snow mobiles and dirt bikes. And just sorta abuse the thing plus teach people how to ride on it. But probably not even going to bother cost less just to sell it and buy a ktm 390 or something similar.
Because I'm legally not allowed a bike bigger than 125cc 😢😢
50cc mopeds are fun, if you tune them a little they can go pretty fast haha. 60 mph maybe does not sound like much but when you sit on a bicycle frame held together with zipties its different (y)
The life of the engine is greatly reduced it just brings the engine rebuild closer. The piston rings only last so long even with the best maintenance and 2 stroke oil
Stiff suspension, good sprocket ratio, tightened chain, good oil, aftermarket air filter, exhaust, fueling, cdi also changing the tyres is a big help however all this cost's more than what it's worth you may as well swap the engine for a 250 lump
Being skiny, finaly paied up !! I have only 65kg só my bike goes 20% faster hahaa
How much power did an unrestricted Cagiva Mito produce?
back in the 80S on a ypvs raising the exhaust port by abot 10-15 mm made a big driftnets if i remember me Yamaha rdlc 125 did 85 to 90 isss when it wos standers and think around the 110 open so i wood recomend a good porting job on a t2 and gas flowing a t4 but is harder to live whit ass below the power band is shit so you have to keep in the power band ore drop gears to get it gowning
Good overview for sure. Bottom line, Speed=Money, you want to go faster, your either going to have to open your wallet wide, but regardless you'll be opening it often as reliability will suffer because its so far past the original design target. You mentioned the scooter guys with the two strokes, as you said they increase displacement and radically change the port timing where the powerband is abrupt and unless its ridden to the limits has no power and typically will have no bottom end power so at less than 10/10's its not fun to deal with. I've been on a few runs with these guys and the fastest and most modified bikes seize up rather often. Typically as soon as it cools they're able to continue but it does cause damage every time it happens.. I know this might be hotly debated, but it doesn't take research to see those that push an engine past its original power are frequently replacing something, the factory knows this, its probably why they get the design to a compromise level to get it past a reasonable warranty period. Just an opinion for sure.
" I know this might be hotly debated, but it doesn't take research to see
those that push an engine past its original power are frequently
replacing something" I smeel another video coming, I love hot debates lol - cheers for the comment - matt
This is much more relatable when you live in south east asia. Like i do. But 150cc does go up to 62mph(bad engine condition tho). And my bike and me weighs a total of about 170kg-ish (asian. Im relatively small and light). But boi when 98% of the population is on less than 250cc bikes. We push these engines so far, and still use it daily. Like a 125cc engine bored up to 180cc and big valves, aggressive cams, big carbs. Suddenly your 9hp is now 22hp, just like you say. But what is not 'true' from what you say is their reliability. Guys that goes up in bore usually also uses forged parts in the process too. So reliability isn't compromised as much as you might think. Sure it still will shorten the lifespan, but the whole bike itself usually goes too old first before the engine even breaks down, so not too relevant. And i personally am riding a bored 150cc bike (from a 135cc) daily :)
Going from 135 to 150 really isn't a huge increase or worth bothering with is it? That's only an 11% increase, factoring in the cost, work etc..........
The Workshop yes if my intention was just to bore up. That is way to small. But when i did it, it was because the conrod was shot, and the cylinder block was scored to hell as an effect. So i needed to change the conrod, piston, and cyl block anyway. Going up to 150cc was like as extra $10 to the already big list of parts since i'm just using a part from another 150cc engine that was from the same engine family. So it was still a plug and play upgrade
Koolkei jupiter mx ya gimana enak gak
susah bilang. mx ane skarang udah sampe 106000 km. ane tangan ke-3 dari sodara smua, tapi kondisi pas ane dapet udah kurang sehat, dan sampe skarang belom full sehat. jadi gak bisa bandingin sama mx standar pabrik enak yang mana.
To make his 125cc bike faster my friend made his own sprockets and put a large one on the engines side and a small one on the wheels side. It reduced the torque and increased acceleration times, but upped the speed to 100mph
Im 15 and ive been considering buying an ktm exc 125 cc, and turning it into an supermoto. i already own an yamaha mt 125 (2018, 2020 and 2021 are hella ugly). where i live riding fast is a lot more about skill than top speed, i for the most part drive faster than my older friends with bigger bikes, but if the curves are far apart or your able to keep a high speed through them they disaper infront of me. The exc will have an higher top speed and much faster aceleration. ive seen videos of modified exc 125s gap 300cc bikes. is this going to be worth the hassle in performance. Money wise i will probably get more back when selling than i used on the bike so thats no problem.
Sorry for noob question but I saw a video where they said if you care only about acceleration and not top speed put in a bigger rear sprocket or a smaller front socket. Is this really true?
yes to a degree, I'll be doing a video on this this weekend - thanks for the comment - matt
most of it depends on the bike, if its a rc 125 of yzfr 125, the engine has the potential for more power but its restricted to make it learner legal, put a remapping chip in and your done, but bikes like a ybr just don't have the potential for more power in the engines
Имам 125cc 4 stoke скутер :) Какво е по-добър мод от по-висока скорост? Сега в спускане имам 134 км / ч = 83 мили! Най-голямата струя е добри възможности?
Can you engine swap any 125 bike with at least a 250cc??
a 125cc 2 stroke bike can easily go up to 80-100mph if you ride and tune it right
yes but they stink and are unreliable and sound awful, get on the bike and it sounds like a chicken chaser get off the bike smelling like a BBQ.
125cc 2stroke race-engine can go even faster!
What about if I took a cheap Chinese bike and put in a aprilia rs4 engine n changed the sprocket the back tyre and a big bore kit and wider tubing aswell as replacing some of the steel parts for carbon fiber
What about fitting NOS system to it? .........hold my beer 🍺
What if you got a 125cc 2 stroke? I heard of a guy that had a aprillia rs 125, he just pulled a restrictor plate from the exhuast system, and the bike then ran so much better..
Matt I noticed my glr125 did 65mph after 8000 rpm, which is where honda claimed was peak power, I didn't understand why top speed was after peak power. I upped the gearing and it'll do 70-75 now.
Be good if you covered the 2 stroke side abit more as it would add a lot more depth to the explanation... but the simple answer is most 2 stroke 125s aren't learner legal once derestricted or modded. But there is a lot of interesting stuff to cover, squish, ignition timing, carbs, reeds, exhausts etc. I built a rs 125 with lots of engine goodies and would like to think it made the 33hp everyone bangs on about... vhm head etc etc etc
Will be doing, I have alot to do but a lot of time in the future. One of the next projects coming up is the AM6 rebuild where I can use that engine to go through the things you've just mentioned. I do have video from 2 years back that does cover alot of this. Just look on my video tab on my channel. - matt
Kids! If you take your standard sprocket set and replace it with racing sprockets with less teeth up front. You WILL notice a dramatic difference in performance and acceleration.
Cheap enough upgrade too.
Or of corse, get a 2-stroke.
You'll be striping it down every week but you can go as fast as you want.
I've done 135 kph (81 mph) on flat just with a k&n filter mod, full stock, it cant go above 135 not even in 89° downhill xd so its quite good for a 125 i guess
Just do a sprocket change(
The cooling problem when a stock engine is pushed for maximum horse power is rarely addressed in my opinion. The heat takes a horrible toll on little engines.
Very good point, and it will be addressed - matt
I have a honda bike 125cc and its 98kg only in stock condition... I have use some tweaks like i removed the mudgards headlights etc but it can go only 120kmph which is not enough its 11.6hp what could be the issue???
I'm no mechanic and I'm relatively new to the motorbike scene. I'm not trying to zoop up my 125cc for 1-3 hp gains but really just a random question. If anyone know, as there seems to be alot of people on this video who knows what they're talking about. (I'm 33 BTW and o ly riding a 125cc on a cbt to get used to bikes before I do my direct access and get a big boy bike) but that aside my question is. Why will my bike some days sit comfortably at 65mph on a flat and other days struggle to get past 55mph? I know environment can change ie wind and inclines etc. But throughout the summer on windless days it was like the bike had a mind of its own.. Is there anything I could be doing to stop it getting to its full potential or is it purely cos its a 125cc and it decides when it wants to go faster lol? I've been had 78mph out of it downhill wind behind me lol but I'd just be happy if it sat at a constant 60mph on a flat
Air density. This is how much oxygen is in the air. Both air pressure and temperature effect this.
@@dirtygarageguy ohhhh that makes sense thank you for not being condescending etc lol but if I don't know I like to ask we all knew nothing at one point.
This is probably gunna come off sarcastic but this is a genuine question, the Honda CRF125 is their 4 stroke single air cooled off roader, and depending where you look the specs vary from 20-24 BHP, which is vastly better than all over 4 stroke 125s so what is in the engine that makes it so much more powerful?
Great question -
1) Engines
CBR125 (street bike) Bore x stroke = 58 x 47.2mm Oversquare
CRF125 (offroad bike) Bore x stroke = 52.4mm x 57.9mm Undersquare
The CRF has a more torque engine - great for low down aceleration.
2) Weight
CBR125 = 137 Kgs*
CRF125 = 87 Kgs*
(*neither state dry of wet weight)
40+kgs is shit loads, that's nearly 50% of the weight of the CRF. This helps with acelerarion
3) Gearing
CBR125 = 6 speed
CRF125 = 4 speed
This demonstrates that the CRF is designed to acelerate fast that is the main focus. As the CBR is designed more for top speed than aceleration, due to the fact that its so heavy means that they have little choice.
The summary is that the CRF is eating into its reliability hence the 6 month warrenty vs the CBR's 2 years with unlimited miles. The CRF engine is a torquier engine and like I always say - torque is king.
The Workshop so if the engine is geared for torque not top end speed, what would the top speed look like let's say if you did an engine swap? Hypothetically of course
If the engine produces more power then a higher top speed, but the CRF is designed to give up most of its power early on, so your top speed would be higher, but you're oribably gonna run out of road before you reach it.
Secondly the engine will go pop sooner, higher torque means higher forces
How could an aircooled 125cc ever make double the horsepower of a watercooled 125cc i know speedway bikes are aircooled and make big power but do they almost overheat in just a few laps
I bet you a dollar this video attracted thousands of spotty teens keen to get their wee put put puts to go faster and they where disappointed lol... Now did that Brock the Cock bloke not manage to gain another horse by grinding the fuck oot the pads.. lol .. Think i'm on video thousand out of thousands Workshop videos.. Great channel.. :)
And to think, learners used to be allowed out on the roads with 250cc 2 strokes.
I had a Suzuki rgr 125 gamma (two stroke) years ago and that was factory deresticted.. no bore kit, no sprocket or exhaust change. That thing would do 112mph.. it flew! I was 10 and a half stone. Dont make bikes like that anymore.. it never broke down either and I had it two years.
speed is not affected by weight, its just how fast you get there
by that logic you could put a small planet on the bike and it would still go to 70mph.. dont think so
What about the X30 Go Kart Engine and the rotax 125 gokart engines?
They make 25-30hp
And they last 5 minutes
No they dont last 5 minutes.
My mate has a 125 rotax and to keep that 30hp he need to rebuild the bottom end every 30 hours but rotax say it only needs to be done every 50 hours and the top end needs to be done every 15 hours. This is to keep 100% of the power to competitive usage. For an Engine used for weekend racing that sort of maintenance isn't that bad.
Because 50 hours is a long time? And I didn't literally mean 5 minutes or 300 seconds, are you dumb?
No I'm not dumb im just defending my favourite 2 stroke 125 engines.
Plus 125 4 stroke engines are crap i don't even know why people even decided to make them. 2 stroke engines are far Superior in these smaller packages.
While it'd only work temporarily it might be pretty easy to use a 12 Volt cheap ass Amazon electric turbo to add a few extra ponies for passing. Would be fun for certain situations.
Probably not entirely worth it but bore and stroke kit. Turbo or super if you can set one up small enough. And then just work on tuning flow and effiency as reduced or increasing pressure and other shit can affect hp a bit. Potentially add an extra spark plug for better burn. Reduce the parasitic losses. Better intake and exhaust. Potentially figure out a cheap way to DIY a ram air set up.
Then like you said reduce weight. Play with gearing. Throw a little nos.
Got myself a 2007 yamaha xt125 R, 10hp, "naked" of course it being an offroad oriented bike. I was able to go 110 kmh in the highway with some juice still in there. Thought through it and found myself an wc top plastic cover, cut it down, made some mounts in the front fairing and woo now she does 120kmh, as a note, i test my top speed in the same highway straight, a level straight with not much wind. Aerodynamics when no ponnies will do you a lot guys.
Is a 4 stroke 125 going to have a higher output that two stoke 125? I would assume a two stoke burns twice the fuel than a 4 stroke giving it a more constant feed of power?
"Is a 4 stroke 125 going to have a higher output that two stoke 125?" - short answer - no
im glad i see someone who talks like me xd
Shouldn't top speed by limited and controlled by top end RPM and gearing? Do engines gain that much RPM just via weight reduction?
reducing the weight with an engine that weighs very little doesn't help that much.
What about upping a tooth on front sprocket for a little more top end cheap
Hi matt my names will your vids are very good I have been enjoying watching them for a month or too now. very funny when you start ripping into people who think there clever than the manufacture " hard run in lol" these people honestly just do what manufacture says there not trying to catch you out there just looking after there special engines
i have a 125cc 4 stroke 5 gear but i onley youse the 5 gear down hill and flat outs. cors its chokes its self in 5 gear wot to due?
well how did 125 sportspikes in early 2000s make 53 or so horsepower like the aprilia rs 125 but now they all are pushing max 15 hp i wonder how you can make the engine produce the same kind of power that engines used to.
If your heavy it will really effect The 14.7hp and how fast you go.
don't forget how drag increases with speed. so that 10% in speed is actually more like 3 probably. another great video, enjoy them alot.
like this - ruclips.net/video/IGh0s_ToWAw/видео.html
Here in finland when you are 16 you can drive 125cc and i think that not most of 16 years olds doesn't weight 100kg so if they weight about 65-80kg so how fast that will go ?
are you being serious?
had a tzr 125 with the power valve opened up, let the clutch out nothing, wait for it still nothing, all of a sudden WTF new undies. great vids
john Clarke why not just have the ypvs working? Then you get the little bottomend there is and the same topend power.
Adam Berggren needed a licence to be able to get one back then.
there are loads of mods to make a BIG difference especially if your bike is released in country where they don't have the same restrictions , a few hp on a bike that has 10hp will feel like a new bike
open up the exhaust
open up the air flow
increase the jet size or add a bigger carb
increase the bore if for racing
loose weight
"open up the exhaust,
open up the air flow " makes fuck all difference. The direction of the wind, or how fat you are. Meaningless.
"increase the jet size or add a bigger carb" - my favourite one. Try it - it doesn't work.
"increase the bore if for racing" - then that's not a 125 is it??
Want a decent learner legal bike, DT125's are still the best option. Cracking little bikes.
You'll still need a bus pass though because most of time they'll be in bits in the back yard. But at least you learn how to stick a new piston in and learn more about your machine.
Paul Sheehan I've got a YZF R125 and it's a little beast
JPC Rider Still not as fast as a dt125 but the r125 is definitely more reliable
YZF125.... isn't that the one that sounds and goes like a lawnmower?
martin allen, nah thats almost every 4 stroke sport bike in the 125 series
The cagiva motto does a owner had a one that would push a 170kmh on the clock wich is like 108 mph and I only changed the jetting and exhaust thing was reliable and looked good I don’t care what anybody says the cagiva or the aprillia rs are two fastest 125’s of all time
theres no replacement for displacement.
goddamnit thought i was being clever then bam you said it
Matt Dennis cough cough 2st cough cough
But everyone seems to think big cc's are just unnecessary. Speed limit is 70mph why would anyone need more than 125cc
Chris Hart To go fast you need more power
how to:make you 125 faster
make it road legal and change the engine :D (and you are set)
buy a big bore kit
change the sprocets
change the air filter
and thats pretty much all the mods you can do to make it faster
No replacement for displacement. Love that saying.
In Finland you can ride A1 class bike (125 or less cc and 11kw (about 15 horsepower)) at an age of 16. when ur 18, you van have as many ccs as you want but only 35kw and it has to be restricted from max 77kw's. at 21 you dont have any limitations.. weird isn't it....
This is the EU bike license regulations, same here in the UK
I also have cg 125 of honda that is banned and it does 130 km/h every single time without any alteration. Old is gold
@MALIK, S vlogs bhai sai ke ra hoon
@MALIK, S vlogs bhai google pe jao aur check karo all over the world ye bike ban hai is ki awaz ke shor ki wajah se
@MALIK, S vlogs aur bhai 130 tk jaati hai per ziada der ke lie us speed pe ni chlani chaye bcz engine top capacity joti hai tbb
@MALIK, S vlogs bhai me Pakistan me hi hoon but cg baqi ksi country me allow ni wahan chlao ge to challan hoga chalane nahi den ge
And ji mere pass 2 cgs hain 2018 model aur 2020 model
Weight reduction wont change top speed at all except for a tiny tiny bit from reduced tire friction. Top speed is purely a matter of drag vs horsepower.
is a 2008 CBR 125R with 2400 KMS still worth 300 Quid? nice shape, just cracked speedo cover and need the brakes bled.
Is it worth it?
@@dirtygarageguy yes, worth buying 1 at that price, since the 125R came out, a lot of worry 300 contenders like rhe cbr300r and yamaha r3 are available but at a totally higher price plane, thoughts? This is for starter/learner 🚲 bike
hope you enjoy the amount of maintenance
top speed is defined by wind resistance , the loss of weight will just make it accelerate a little faster .. then wind resistance becomes the brick wall , you need more "real" power to make it go faster.
Memories... Damn does anybody even remember there was "legal" 125cc spiting out >30HP that you could buy and run without messing around.
Well they lasted 6 months to 1 year before the engine needed serious intervention and the power band was narrower than the waist of a bulimic. LOL :-)
But they where on the market side by side with 125cc 4 stroke for anybody who really wanted to ride long and cheap.
I still recall 50cc with a boost, usually 75cc and a FEW more goodies overtaking on the road with me seating comfortably at 130km/h and they just passed, screaming like crazy. :-)
Yamaha tzr: Water-cooled 124 cc single cylinder two-stroke. 30 hp/ 11.000 rpm, 18 Nm/ 10.000 rpm.
Suzuki rg: Water-cooled 124 cc single cylinder two-stroke. 33 hp/ 11.250 rpm, 21 Nm/ 11.000 rpm.
www.motorcyclespecs.co.za/model/yamaha/yamaha_tzr125rr%2094.htm
www.suzukicycles.org/RG-series/RG125-Gamma.shtml
Peter Lindström - That's it. :-) Along with those gorgeous Italians like Cagiva's, Aprilia's, Gilera's, etc...Real pocket rockets for anyone to ride.
The workhorses of the real world like Honda CG 125, CUB and alike's shared the same roads with 10/11hp engines designed 20/30 years earlier. When the latest option is what we can get today makes us wonder about "evolution" written out by the stroke of a government pen.
Nowadays it's emissions, driver's license restrictions and a lot more. :-(
I had a brand new Aprilia Rs 125 when I was a lad 2 stroke......within the first week of having it took it down to my local aprilia dealer who at the time i knew to get it de-restricted..he took it in the back snipped a wire in the tail unit told me to be carefull on it and steer clear of the old bill. Jesus Christ it went like a lunatic ....a proper angry little bike. After speaking to a lad who club raced the same bike he said they were 33bhp....I remember racing a bloke on a 600 bandit down a long straight and he couldn't get away I was laughing my nuts off....Aww them were the days 17 yrs old riding round like headcase thinking I was a grand prix rider when really I was just a snot nosed little shit on a 125. Long time ago now I'm nearly 40 great memories though.
Kawasaki GTO125 with a stock 17hp 2 stroke motor is a teenage 125cc dream come true. Has anyone experienced riding it? Touches about 90-97mph
Although I agree with everything said in the video if I was looking to buy a 125 and wanted to improve it as best I could I would buy the older model CBR because it's smaller in size, relatively cheap, lighter than the r125 and narrower tyre sizes so less friction and wind resistance. It also produces good power to start with and an easy upgrade to 150cc as there is also a 150cc model in other markets.The r125 is physically much bigger so although it makes slightly more power there is much more motorcycle to push through the air.chinese bikes are fine nowadays and there is a wide choice at very good prices plus good spares back up but the engines make only 12bhp at best with many only 10 ish bhp although there are many big bore kits cheaply available . The CBR just seems the best all round bike in terms of quality, power, weight and upgradeability in my opinion so that would be my choice if I was looking at having the fastest 4t 125 ( with an obviously illegal cc upgrade!) At a reasonable cost .
Cheapest way really. Put a bigger cc engine in. Or have it tuned at great cost (over a bigger cc engine) or spend loadsamoney on air filters +exhausts to have no noticeable gain. Best thing tune the speedo. We did 90+ mph (Yeah we all - sensible knowledgable people know 72mph was absolute max on a testtrack) in the "olden days" in 850cc Mini´s (std engine ¨cose the speedo reading was SHIT, but we wuz wankers and wanted to believe it. Same as people today. Innit bro?
i get 80mph out of my dt125 and i could still get a lighter flywheel ported transfers 1mil oversized bore and sprocket gearing changed for more speed
My 125cc did 120 once, Also so did It when I rode it off a cliff and broke 4 ribs and an ankle.
Was that 30 feet per second per second.
@TJ's Garage I imagine it reached that speed going down the mountain, and probably so did I to think about it.
Not on road it maxed at yeah about 70, but that's only when it was up and running.
A very rare thing indeed 👍
Best you can do is change front and rear sprockets to around 20% shorter gearing, have to work hard for top speed but you can rip around town and power wheelie in 1st. Should hit 60mph at peak power in top gear still which is is about all you can hope for against wind or slight uphills, plenty of speed for anything below a dual carriageway. Could maybe hold 65 reliably with exhaust etc but easily 6* the price of sprockets.
Raising the idle to around 1.5 to 2* the stock setting will also help get of the line and get rid of jerk and stall on overrun in combination with the previous.
I've got a 125cc crosser but it only goes 45 mph ish it's kinda annoying bike is a SkyTeam ST 125
RD 125 LC ypvs fully tuned and gearing up for top end . rider: 8 stone . Like sitting on a caterpolt
Type of guy that cant do math but can build an engine, legend...still thx
Pretty much most those 125s are actually manufactured to produce that bhp and not restricted
Yes of course they are, I don't get your point?
I agree with the principals but your maths isn’t right at all. Air resistance isn’t linear. A 40bhp bike will do 120mph if you’re lucky. By your maths it would do 240mph.
Hi. I watched the video and read all the comments. In my opinion it all got a bit out of hand also a bit childish.
I have a 125cc motorbike ( not brand new but nearly ) and when i first went out on it i thought that the stock exhaust was somehow restricting it, the sound and feel when in high revs felt like it couldn't get rid of the exhaust waste quick enough. So I bought a full brand new aftermarket exhaust for it, fitted it and took the bike out i noticed straight away in high revs the bike felt alot better and felt like it was running to its full potential. I did think it increased my speed through the gear range but very slightly only.
So the question is do you think getting this new exhaust was a waste of money and time.
The exhaust cost £220 ish.
1) you didn't feel the exhaust being restricted. No one on earth to "feel" that because there's nothing to feel.
2) 125 bikes go from slow to not so slow. The fact that's they have 125cc is literally why this happens. So do I think £220 is worth it? For me, no. I had a 125. I wasted that kind of money on it. And as you can see, you know how I felt about that.
You can spend your money on what you want, but what I said about saving that money and spending it on a bigger bike in the future is a fact. Saving that money will make it better for you in the future where it counts. For example. Spending £200 on brake pads is common, and when you rapidly slow down from 100 to 30mph, you notice. My old 125 couldn't do 100 mph, never mind slow down from that speed.
@@dirtygarageguy Why save money to buy a bigger bike, i chose the 125cc i am not getting a bigger bike. Bigger is not always better. Also i could feel that the exhaust was restricted. You do not have to touch to feel. Because i FEEL like you are been deliberately confrontational.
Bigger is not always better, but it.is a lot of the time. Have you ridden anything bigger than a 125?
Answer me this. What did you feel exactly?
Oh and what bike are we talking about here?
@@dirtygarageguy lol I FEEL nauseous reading your comments.
serious question though... aprilia rs 125? de restricted... its stil a 125cc but much, much quicker
Imo a 125 can get you moving , I beleive with another cylinder say 250cc twin would give best of both worlds not too heavy a bit more go but will yhe same frame work with a little extra breaking capacity ...and as you said is it worth the work ..
So what about the Honda rs 125 ?
My friend builds race scooters and recently he built a C group (stock) one, that produced 16hp at the wheel. Things like tighter tolerances, drilled out lightweight / DLC coated parts, heat isolation for the intake, the magneto rotor is so lightened out that it isn't even magnetic anymore lol. It was amazing watching him build it, and it was amazing to ride, you'd never believe it's a stock 125cc with stock (polished ports) cyl.head. HOWEVER it costs a fucking fortune! You can buy a good motorcycle for that.
So for people who want a faster 125, unless you're racing, just get a simple big bore kit that you can install yourself and don't waste anymore money ;)
"Things like tighter tolerances" - you mean clearnaces.
The Workshop aw shit! I mixed them again
bro in my country there are Honda cg 125 bykes, there are 11hp 100kg (bike weight)with top speed of 110kmph GPS.
people make them go 150kmph
User X they dont. Thats a lie.
may be 150 is a lie but stock cg125 goes easily on gps 110 i do it daily
Kmph? Interesting measurement... Is that Korean made-up per hour
Cg125 does not go any speed easily maybe 35mph it's even a pushrod engine until the very late model even then i'm not sure they don't rev for shit nothing with pushrods ever does
Did I just heard a crow? Anyway that's a Good Video
Skinny wheels and full fairing covering the rider as well and if you're a big guy just forget about it and get a Harley instead :P
Would it be best to replace the 125cc with like a 250??
Lol no, it'd be best keeping the 250 engine in its own chassis, like the god lord intended
what i dont get is why you cant produce more power out of the engine
because if you look on an 600cc sportbikes with 110hp (for example) and divide the cc with 4 (4 cylinders) you get 150cc for every cylinder.then divide the 110hp with 4 (again 4 cylinders) you get 27,5 hp for each cylinder.so why you cannot make our 125cc bike easy over 20hp?of course not near 27hp
Good question will do a video next weekend