YZ250 Mod with 8 More Horsepower
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- Опубликовано: 6 окт 2024
- We got a 2023 YZ250 and immediately took it down to the frame to rebuild it into the ultimate racing machine.
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#yamaha #YZ250 #yzfamily
Jay… you are the man! Tom just did my 1993 CR250 complete engine, just waiting on it to arrive…. I’m betting it’s going to be a ripper!
Nice bike. Tom built me a YZ315 stroker a few years back. We had it at RBSR 2019. Thing is fast and most importantly, smoother then stock 250!
I love your dedication to the tire change!
6-8! hmm might have to buy and youtube that
Yes please I’d love to see it on a dyno
PLEASE, do....
@@Motoinc I think 6-7 with jetting, fuel, pipe, reeds and port and head vs a mediocre/poorly tuned stock bike is reasonable. But just porting and head work worth that much would be amazing!
@@HPRaceDevelopment .
Yeah it could be with a bad tuned bike BEFORE ...but anyway when making this big of claims it should be woth a Dyno sheet. I follow your channel and hope you test it.....and the beef would give you viewer for sure haha you been here before 😂if the claim wont show on your dyno. Cheers from Sweden
Thought he did carb, reeds, head for race gas only, port work etc. think the only thing he left off was ecu and matched cases. @@HPRaceDevelopment
That YZ 250 is real nice sounds awesome
That's just awesome..I once had a 2004 yz 250 2 stroke..rebuild it bottom & top..& man it was a beast fs👍😁🔥
The 2-stroke YZ250 may be the tallest bike made, and that is insane. I corner so much easier with my lowered bike and the bars pulled back for riding. Much harder to control the front end with the ape hanger set up.
Man, i love your 2 stroke content! Best regards from germany 🙂
So cool to see how it’s coming along. Excited for the next part
I must admit, it sounds absolutely amazing 👏
When are you engine builders going to realize a big bunch of us out here want a 2 stroke that makes a great woods that has smooth power from bottom to top with no big hit anywhere let's face it 90 % of us aren't moto-crossers we're woods an trail riders we want bikes that's controllable an pulls good right off idle an smooth to the top build that 2 stroke seems no one does anymore oh yeah forgot about the European bikes no body can afford
Start building your own engines!
Get a Yamaha WR250 or WR450 that's exactly what they are made for . They make bikes for all types of rides and riding styles . 2-Strokes and 4-Strokes ; I'm betting they are working on a 2-Stroke 300cc bike probably with electric start . I wouldn't put nothing past Yamaha R&D Department .
Get a YZ250X model that already has slighlty lower compression than a regulay YZ250 then throw a flywheel weight on it and its a woods machine. Handles bogging as good if not better than a 300 ktm/husqy.
Get an older model ktm 300 or 250 exc
That’s called a 300exc
that's pretty cool. I'm getting back into it. I used to ride back in the 90's and 1988...I got to get me my new Yamaha 250 2 stroke monster energy edition...I GOTTA GET BACK IN AND RIDE AGAIN AND GET ALL MY STRENGTH BACK!
If you are iunder 5'10" tall, I have a set up fro you. The newer ones have a very thin seat, but i had 1" taken off mine (tallest bike made). I also lowered the suspension .75 inches on both ends, and set the sag at 98-97mm. Now, the thing corners with out a berm. It is said the bike has good low end power, but those testers never rode a 97 KX250. I greatly improved the low end power (I port/stroke 2-stroke engines for a living.), with out much if any loss of top rpm, (did not put a tach on it though, I forgot when stock). It does not hit real hard, but smooth and powerful now. I went with the FMF Gnarly pipe (tuned for a lower rpm target than stock), use V-force reeds with no stock aluminum spacer plate, (more primary compression that is the lower end crank area, and more complete case filling), and lowered the cylinder by not using a cylinder base gasket. That gains compression (need 100 octane fuel now. I mix 110 with 90 alky free pump gas), and lowers the exhaust port to better match the lower rpm pipe. Squish clearance is a very good .048" now. The stock suspension spring rates threw me for a curve, but i fixed it with the proper springs for my aged heavier weight,--to perfection. I took off riding for 18 years, and I say this bike required more work to make it good than I have ever had to do with a stock bike.
Basically, they made the bike a high revving bike in an effort to keep up with 15 more hp of a 450, and it ain't gonna happen. That made the bike pretty bad for most other forms of off road riding IMO, (plus it's ridiculous height). But now I think it is the best bike I ever owned. Still using the stock gearing and weigh 200 lbs now. I am going to add 2 teeth on the rear for my next set of chain/sprockets, and it should make it even easier to loft the front end at low rpm's when needed. I am not a fan of the slow, rocky, root laden slippery trails, so I don't even think I need a flywheel weight. All the mods are reversible if needed (like raising the cylinder back up to use 93 octane gas). I know, coming from the same era you did (started racing in 84-2001), you will love this set up much better than the stock bike, that is not really great anywhere, but can be made great for anything but a modern speedway MX track against 450's (unfairly IMO).
"and lowered the cylinder by not using a cylinder base gasket." Make sure you use a good gasket sealer. you do not want a leak there. I clean the surfaces with brake cleaner, and use a 3M product Nitrli gasket adhesive (gas proof) # 847, and apply it with a syringe for a perfect bead, let it cure for at least a day before starting it, but the heat makes it a really good seal that you will need a rubber mallet to remove. Best gasket sealer I have ever used.
Right on!
Like to see dyno chart should be impressive with plus 8 that's around 55 hp not bad.
Yamaha claims 45hp stock, and I am sure that is with better jetting then what is sold. There is probably 2 hp to be gained with the jetting alone, and he should be between 51 and 53hp. Damn good.
I had a pretty gnarly high compression build yz125 back in the day when we use to race. Early to late 2000 and I remember having to rebuild it like every 15 hours lol not that it blew up but we were ringing that thing out. My buddy Dayton beavers had a rm125 making lie 41hp it was sick
Lol ! Your buddies name Dayton Beavers ? Reminds me of my glory days , I can't stop laughing 😂
@@kruse1105 lol I'm guessing you know the name. But yea he's a friend haha
Can I ask what you did ?
@@Stealth164 it was just a really high compression build. Obviously all supporting mods like hinson clutch an stuff. Yours asking about what I did to the bike right. We did a ton I can't remember alot I mean this is 15 years ago lol
What about if you only would install a that aftermarket pipe? How much hp increase ''alone'' would it do? And maybe some richer tuning on the carb on top of that.
Cheers.
Peak power may not change much with a after market pipe, (most stock pipes do make good peak power today), but shifting the power lower (for example) can be had with a after market pipe. If a pipe did make more top end power, it would probably lose more low end power, and this bike can use more low end power.
Gotta love the good ol yz,
I cant wait to see your comments on the track
Awesome, I wish Yamaha would get back into 2 stroke modern engine development. It would be a fantastic motor and bike.
I'll bet they are working on it , in secret . 😊
What do you mean by "Modern engine development"? The EPA forcing fuel injection that will be outlawed anyway as tougher regulations stifle gas engines? if you know what you are doing, or know somebody who does, you can get the power you want from this engine, high rpm or lower rpm power. The dictatorship does not have the right to tell us what to make and buy,---so I will never support that terrible force on the manufactures.
You can also just get a phathead so that way you can swap from the highcomp dome to standard if you need ti run regular gas etc
Or keep a stock head also. In think in 2011 or 12 Yamaha lowered the compression, so get the old one for the stock head IMO.
@@EarthSurferUSA2012 lowered compression, 2003-20011 had 59 crank horsepower
Bring it to Utah!!! The single track is calling you!
I don't care what MXA says today. They do not know how to jet a carb anymore. I have the 2019 model, (same engine and pipe), and the jetting is horribly rich. MXA said it was perfect, but it hardly warms the water up as it spits un-burnt oil all over the back of your expensive jerseys from the silencer. I have moved the needle to the last top groove, (one groove) raised the compression (hotter burn) helped, and it is still running rich and spitting some oil. Going to a #40 power jet, (the one I think is not needed, and causing the richness) next. I may end up using the next more lean needle though, (which I have ready). I will deal with the main jet at wide open throttle, after I get the thing from spitting on me and making exhaust oil mess everywhere. It is the most rich stock 2-stroke off the floor that I have ever had, and it was amazing the dark and wet plug with the stock jetting did not foul.
You can gain up to 3hp with cleaning up- the jetting on this rich pig, have less chance of cold damaging your piston (takes for ever for the water to warm up, and many riders just take off riding to early.), and better running in all usable rpm's. plus, you will stop ruining expensive jerseys.
MXA is not the technical mag it used to be. And to test a bike for publication with out knowing how to jet the carb is just unfair. What a shame. Doug in Michigan
Hey mate, I've got a 2019 YZ250 and I run the N3CJ needle (ive ran them in all the YZ250's ive ever owned) its the next needle down leaner from the stock N3CW, a 48 pilot (u can run the stock 50, its not "that" rich but drop to a 48 if u really don't like the 50) and I actually jet it richer on the main, up to a 185 insteadve the 178 but I ride the bike WIDE open most of the time as I'm lazy with shifting haha and I don't get 1 drop of oil out the muffler.
Oh and that's at 40:1 fuel ratio.
Oil to gas ratio can throw off jetting since it makes the fuel thicker… so more oil = leaner air/fuel ratio.
Just something most overlook
Oil to gas ratio can throw off jetting since it makes the fuel thicker… so more oil = leaner air/fuel ratio.
Just something most overlook
Balanced cranks are sooo nice to ride your hands dont go numb 🤤
Bike turned out amazing Jay 👍👍
I'd like to fuel that with my new STIC Super X2 38/40mm carb. Would be more power than Jared Lesher's SX/National HP tune, bc he only uses the original STIC metering block. My stock 200SX is now mixing it up with faster riders. Pilot jet stawk is a 45, now it's at an 80 with a 200 main combo! The pilot at intermediate idle crosses over to just above the main jet, under hi speed from the vapor filled intake bell...YAT No Choice!
With the larger carb venturi, air flow is slower, so you have to jett bigger for the slower air to pick up the right amount of fuel. Low end power sill suffer.
Have you experimented with any of the metering carbs like Lectron, Smart Carb sc2 or XNTG?
Hello, when mounting fmf fatty and shorty on a stock 2023 yz 250, you should change the 178 main jet for one of 180 or 182, thanks in advance, regards
Go b7y the plug color at wide open throttle to determined the main jet. I doubt you want to go richer than stock with any mods. At least that is true for my 2019 bike. Most rich jetting stock I have ever seen. Un-burnt oil even ruined 3 of the backs of my jerseys from droplets emanating from the silencer. Way to cold.
Sounds so good. I think I’m going to have to run that fmf system on mine 😏👌🏻
What else would you run on a 2stroke?
Dam sounds soo crisp. Love it
Cool. I’m partial to ProCircuit exhaust. Better power and sound.
talking about jetting try the magic Suzuki needle from I think 2006 rm250. I know back in the day they was hard to get cause everybody with ktm was putting them in their carbs.
I was going to say "No way 8 more HP!!", (would be about 53hp), but this is Tom Morgan, and there is a lot of work done that I am sure matches up (the work done compatible, not mix matched), it is probably right up there with the works Honda's of their 2-stroke hay day.
That's why Dyno tuning is a great help in making sure all the components work together .
@@michaelheiss4456 Not really. I own a dyno, (small gas engines). First, there is no calibration for them, and that is basically the reason why we get different numbers with the same set up on different dyno's. But, if you are using one dyno, it does show you if your power is going in the direction you want after mods.
But more importantly on why a dyno is not the "tell all" of engine power. It reads the power at wide open throttle only. So it really does not measure well all the time with how the bike works on the ground, using many throttle actions. For example, if I had an engine that was a dog in the lower and mid range RPM's, but ripped at full throttle , it can make great numbers on the dyno, but be pretty hard to ride on the track. This is why the best engine tuners also test on the track after some engine mods and dyno testing. They often get burnt if they don't. 2-strokes especially.
Doug in Michigan
Nice Gen-X build, Jay
8! Over stock that’s crazy fast
6-8 is what is claimed. Better jetting than stock alone is probably worth 2 hp or maybe more, and better running through the entire power curve. I am sure the power increase is in the top rpm range, and I am sure the lower rpm suffers some because of it.
Hey you guys could you please tell us a good Main and pilot jet number’s for Southern California ❓🙏🏼❓🙏🏼 I live in Redondo Beach California. PS. I have a stock 2003 RM 250, Pro circuit fatty pipe, VForce 3 reed’s .. I just had a stock rebuild and I can’t figure out the Jetting for shit ‼️😤 please help 🙏🏼🙏🏼🙏🏼
Stock is usually about 2 sizes rich at sea level . Check what the pipe and reed manufacturer recommends . Make a couple of high speed full throttle passes and ; Chop the throttle . Pull in the clutch and come to a stop . Take out the spark plug and see what color it is . Should be a light brown or tan color . Black is too rich and white color too lean . That's sea level . Up in Gorman ; Hungry Valley you will need a jet approximately 2 sizes smaller . 1 clip groove up on the needle jet and adjust the air screw . Altimeter and Air Density meters will be a big help . Friends always wondered how my bikes ran better than theirs . 😊 Write down the Jets you put in and how it affects the way the bike runs . Don't forget to change them back at a lower altitude . Better to err on the rich side than lean . That's why the chop test .
Nice job. Question - why isn't he taper boring the carb verses straight bore? Also I noticed the head squish area is very large percentage - not revving much higher then stock?
I built a high HP 250 2 stroke of another brand, with all the same mods you've shown, plus I taper bore carb (no straight bore). Big difference. Good choice of pipe too with the FMF Fatty. My engine is 15:1 CR with 0.050 squish and I run AV100LL and love that fuel! I've also tried VP C14 (C-12 is not high enough) and there is no difference from the 100LL except the 100LL is more consistent on the dyno then the race fuels. Just thought to share.
Would be nice to go more in depth with tmr. Biggest performance enhancers would be more peg time, maybe hydraulic clutch or yzx springs to ease the pull in technical shit.
I have never had such an easy clutch lever to pull than my stock YZ250 2-stroke. More power will probably mean stiffer springs.
Ktm has already did all that just buy a sx 300 and that will rip !
8 over ..wheres the dyno tests😢
Nice sweatshirt man 👍🏼
What’s the $$ on the port job on the head and carb
Beautiful but it’s a lot easier to buy a 300 which will make the same power for less money and then if want more power you can get a pipe and aftermarket to go hunting 450 ‘s
500's have a hard time with the new 450's ! Most guys can't handle the power of the 450's hanging on for dear life trying to control them . 😊 It like one cylinder off a NASCAR these days . Some are going to the 350's that can make the same horsepower , but easier to handle .
Really? I find it more expensive to buy a bike engine that the EPA forces on the manufactures. Why do you think a 4-stroke costs over 10 grand?
@@michaelheiss4456 From what I understand, when Yamaha went 4-stroke, the technology came from their road race engines. Now wonder why the tracks are so dangerous fast today.
Looks close to
Schleisman or pine st
I need see a dyno chart before I'll believe it
There are no shortage of dynos that are not accurate at all. (there is no real calibration method.). But if you are using the same dyno, you can confidently see the improvements. But remember a dyno only reads at full throttle. So you can have an engine that is a dog in the power and mid range RPM's, but make great full throttle power peak power. Great looking on the dyno, hard to ride on the track for most riders. In reality, a dyno chart is hard for me to believe totally, unless I know the dyno and ran it.
Love the videos. I’ve learned a lot from your instructional information and for the first time ever in a video, think I’ve found exactly what I’ve often wondered.
In the road test you turned around and started heading back and stated “Right there.” It sounded like the motor was “sputtering” and I believe that is the rich sputter that would need to be leaned out. Is that correct? Is that what you were commenting about?
Again, thanks for the info and love the videos.
Email Jay with questions! Contact info in About tab.
What a nice bike sounds mean
In the first ride video when midrange was spluttering a tad, what jetting change did you do there, just the air screw or needle clip? Running to rich or to lean? Sweet bike , i have the 22 model, still getting used to jetting changes.
Email Jay. Contact info in About tab.
"I'm the 0.3"
He did say “between” to be fair
So this more for moto it seems, hows the low end after? Does Tom Morgan do yz250s for woods racing/cross country?
I always put on the heaviest flywheel weight I can get , it's great for off-road and still plenty fast if you want to take it on the track
Great job
So is this going to be a trail bike Or motocross? Seems like that build going to be strong off bottom and fall off on top??
Nope IMO. It's biggest gains are probably from the mid range to the top end. It is easier to get big gains with higher rpm. Part of the HP equation.
Why not run a Lectron or Smart carb?
I would like them if I were riding different elevations all the time, but I am not. So jetting the carb well,---is just as good if not better. The problem is, even MXA does not know how to jet a carb anymore.
All the money put into that bike anyways why wouldnt put in a smart carb sc2 or a billetron pro 38
The smart carbs are probably great for riding in different elevations and such, because i understand they are self adjusting for air quality, where fixed jets are not. But, if you ride in the same area with pretty much the same air quality, jetting a carb well is still hard to beat.
You should try the Stic in your pwk
sounds sweet
crispy
Is it normal for oil to drip out of the power valve vent line on a 2023 yz 250X
Yes, when running rich, as they come stock. I like to drop the needle one notch, but that can be a pretty big jump. In that case, I make a little spacer about half the distance of the drop, and add it to go only half way. Then I tune the main jet, and pilot of needed.
I just picked up a 2024 yz 250 what’s a good website to order pipe silencer and other parts seems like bto and a few other sites don’t have anything for the 2024 in stock
You can put a pipe on it as its been the same since 06' i think?? Lol
Try calling the people who actually make the pipes. I think they all still use a telephone for the best communication.
That would put that 250 2 stroke in 450 hp territory. Probably torque as well. As a 450 only lays down around 3 to 5 more ft lb of peak torque than the yz 250. It's just a much flater torque curve... on the pipe the yz 250 peak power isnt durasticaly lower than a 450. have you tried the eddie sanders ceo cylinder and 325 kit? Crank works also offers Atomization Surface Treatment (AST)
Roughens the surface of the crank to better atomize the fuel, making for a cleaner and more efficient burn, which leads to more horsepower (2-strokes only)..
I would love to see some results from
You can get peak h.p close to a 450.but you can never get it close on peak tourque of a 450.the pipe on a 2 stroke can't do it.
@Dennis Wilder bud pull up a dyno chart. It's already there . 2 strokes put down more peak torque than 4 stroke. What your feeling isn't peak torque its torque curve. 4 strokes make torque everywere relatively consistently rather than all at once like a mx ported 2 stroke. That linear power delivery or torque available throughout the rpm range equals traction. Rather than a narrow power window spitting it all out at once. Pnd for pnd.. 2 strokes annihilate 4 strokes on peak tq. Worse than peak hp most the time. But power delivery is what wins races not peak numbers.
So given the stock power differences between the 450 and 250 2 stroke. It's not hard to imagine a gain in 8hp isn't going to net improved torque of some value. Not like a 4 stroke were your trading one for the other based on cam profile
The 2023 450 motocross bikes were dyno tested at Pro Circuit.
KTM 450SX-F: 59.94 hp @ 9360 rpm
HUSQVARNA FC450: 59.30 hp @ 9810 rpm
YAMAHA YZ450F: 58.95 hp @ 9840 rpm
GASGAS MC450F: 57.07 hp @ 9050 rpm
KAWASAKI KX450: 56.37 hp @ 9540 rpm
HONDA CRF450R: 56.31 hp @ 8960 rpm
SUZUKI RM-Z450: 54.87 hp @ 8780 rpm
HONDA CRF450R: 37.30 lb-ft @ 6980 rpm
YAMAHA YZ450F: 35.37 lb-ft @ 7250 rpm
GASGAS MC450F: 36.73 lb-ft @ 7560 rpm
KTM 450SX-F: 36.51 lb-ft @ 7190 rpm
HUSQVARNA FC450: 36.33 lb-ft @ 7220 rpm
KAWASAKI KX450: 35.48 lb-ft @ 6800 rpm
SUZUKI RM-Z450: 35.19 lb-ft @ 7670 rpm
Yz 250 as consistently rated throughout the web
..The engine produces a peak 48.8 horsepower (36.4 kW) at 8,800 rpm and 30.6 foot-pounds force (41.5 N⋅m) of torque at 7,500 rpm,
Although I have seen yz 250 torque listed at 32 to 33 in previous years. But every dyno is different they say..
And I've blown up more 450 4 strokes than any other bike I've ridden. So I understand why you might make that assumption off of the old butt dyno. But it's wrong
@@dormantmenace just did from dirt rider 2022 yz250 37.9 h.p 18.3 ft lb tourque.kaplin cycles dynoed a cr 500 fully built and only produced 57 h.p and 42 ftlb of tourque.
@Dennis Wilder that's a yz250f genius. You know the 4 stroke! what are you 17 lmao... oh man.. hey maybe read the article before you go siting it as reference little buddy.
And no that's not a fully built cr 500. It layed down more than than stock.. even with the cr 500 having no power valve. I've owned a 89 and 90... cr 500 was also detuned in 86 as the 85 was to powerfull according to the pros racing it.
Oh man best part is.. I already gave you all the numbers.. and your out here like your gonna disprove FACT. Cause a 450 feels like it makes way more torque.. it does make way more torque!! All across the rpm range.. just not much more at peak.. despite twice the displacement..
But hey you posting the yz250f dyno chart making 18.3 ftlp vz the yz250 stroke at 30.6 ft lb... just proved what I said. A pnd for pnd... 250 4 stroke vs 250 2 stroke.. of mx pedigree.. 2 stroke layed down almost twice the peak torque... how embarrassing
AWESOME
Qual a taxa de compressão não corrigida para yz 250 ?
2.3 people worked on it lol is a miget the .3?
How would this compare to a 300sx stock?
Curious on the numbers for this as well !
@Backyard Bandits ... I think it would be real close... Yamaha really needs to just go ahead and offer a 300cc version anyway & maybe do a 300 X model too... I would have bought that instead of the YZ250 2-STROKE that I bought new in 2018
Who does the work and where?
i just bought this bike and it wont even hold a idle no matter what i do to the air or idle screw nothing changes
@Maximuzz ... u may need to check the throttle cable adjustment.. when I bought my 2018 new from the dealership, my YZ250 2-stroke throttle cable definitely wasn't adjusted right at all... when I would twist the throttle open and let it go, it wouldn't even close and snap back in the closed position and I said something about it to the mechanics in the shop... read the owner's manual for your bike and u might have to re-jet the carb for your altitude and air temperature
I had the same issue with my 2019, (same engine). I ended up pretty much cranking the idle screw all the way in, and setting the air screw to spec. I like a slightly high idle so it does not stall as easily when braking for a corner, and it is pretty much where I need it now. It is the least responsive idle screw I have ever used. I think it opens the slid a bit, so I opened the throttle when turning it in.
@@EarthSurferUSA I fixed it I just took the idle screw completely out and put it back and I was able to screw it in more then before
Any idea on price to do something like that for a 2021 yz250 ? Love the show
Most likely around the same price
No dyno?
What spring rates are you using front and rear ? Great video
Depends on rider weight and skill. If you are over 180 (approx), and using stock springs with the rear sag set,---the front will hang too low, and the handling will be terrible.
For suspension work/advise, I think it is hard to beat Race Tech or Enzo. They can both set you up for your riding and weight.
What would all this cost?
How much did the mods cost?
Think boyesen rad valve and Bill's pipe it runs again better
The turbine core makes more power
Yea sure that's why all the pro's run a turbine core lol
Turbine core adds “back pressure” because of the spark arrestor. Usually makes the bike feel like it has a little more on the bottom end, but in my opinion, then cuts some off the top end. Just my 2 cents.
Who modded the cylinder ?
Link ?
In case you have a attention span of less than 15 seconds, the man was mentioned at second 16. Tom Morgan is one of the few 2-stroke guru's left, and has been a factory engine builder for pro racers since and before Jeff Ward. That guy---is legit. I promise you.
i think this high compresson stuff destroy the durability and the crank bearings.i use low compression on my 250 best durability lowert temp.
What was pilot jet ? 2nd clip ?
The pilot jet does not have a clip adjustment. That is the real low rpm jet too (to like zero to 1/8th throttle opening.). The needle jet (more mid range power) has the clip grooves, and I set min on the top groove, (was 2nd from the top), and it is still running rich.
@@EarthSurferUSA it’s a two part question about a pilot jet and a needle clip . But also has expired in months thanks pal
Why not go with a Lectron or Smartcarb? When you want to build the ultimate racing machine you basically have to get one
Not in my opinion. You can use Keihin PWK Airstryker or even Mikuni TM if you know how to modify them correctly.
New rider here, how do I mod to have LESS power? 😂
Leave it stock. :)
8hp h mmm and testing on the tar
Actually, with today's gps systems, you can measure acceleration in a rpm range, and tell if you are making more power in that rpm range. you just don't get actual HP numbers,---but many dyno's don't give you accuracy either. There is no calibration system for them to speak of.
CDI standard?
Since about 1978.
wxyz... nice
4 stroke suck 2 stroke for good time.... comments coming soon when they get off their phones
Come on guys, the title to this video is "YZ250 Mod with 8 More Horsepower"... and yet not only did you neglect to show the YZ getting DYNO"ed pre and post mods, you avoided even mentioning any numbers. WTF
Believe it or not, there is really no calibration for dyno's. Take the same set up to every dyno across the nation, and you will probably see an 8hp difference. Yamaha claims about 45hp stock,--and that is jetted better than what we buy.
Tom Morgan is one of the best 2-stroke tuners on the planet, and the stock YZ250 is probably the slowest 250 I ever had, so pretty easy for him to improve really.
Factory tuning, factory ecu Map and factory rubber will give you more than 8
It has a carb so no lmao
Factory tuning? You gonna have to crack open Chad Reeds old yz to see any of that.. also the stock cdi (not ecu) is pretty much the best one for the yz. I'm sure spec tires are great, never rode any so idk
P
@@jpesicka492 amatuer 🤣
Max a tuner have get is 4 to 5
Why are you engine braking the bike in break-in so much? At 7:45-> just alot of MMWWWWOOOOOOOOOOO and no pulling the clutch. I wouldnt dare to try that on a fresh piston :D
I know its not that excessive but I'd be afraid of doing it.
Actually, you don't have to worry about the piston. It is the rings that you seat to the cylinder wall as fast as possible, to reduce blow by and tarnish build up on the cylinder walls.. The combustion pressure actually goes over the ring and behind it and pushes the ring against the cylinder wall for the fastest seating. You can see that when you take off the old ring, it will be dirtier on top than on the bottom. And that means you want to break it in where the torque is highest, (highest cylinder pressure). Some builders when refreshing a engine at the track, would even put the piston and ring in dry (no oil on it), to help seat the rings in faster in practice, and ready to race that day.
As long as your jetting and gas mix is good, run it.
Throw it on a dyno
Homie can work on bikes but i dont think he really knows how to make a 2stroke sing
You also want reliability . I built one that screamed and would pass everyone but it wouldn't finish a race without something breaking or blowing the head gasket . But it was fun ! 😅
@michaelheiss4456 dude just can't ride a bike that good get him off the bike... get that man off a the bike
🤙✌
So many claims...no DATA
Basically, probably good for 49hp tho.
@@derek3107 yeah probably
@@Motoinc Don't worry about what Tom Morgan claims. He is one of the best 2-stroke tuners on the planet today. It is also a fairly slow bike stock, (even compared to my 250's from the 80's), so it is easier to get the gains he claims. I would bet it is over 50hp,--at the crank.
Twin turbo diesel it and call it a day
Nobody has figure out a way to supercharge a 2-stroke. The boost just blows out of the exhaust port before it closes.
@@EarthSurferUSA true indeed
You’re stoned if you think you’re getting 8hp.. idk who thinks that, you or ParaPros. I’d bet my house on it. That cylinder and head mod isn’t getting that.
There's no way you can add 8bhp without a big bore kit
Of course you can.and it's not that hard a good head and fuel package can add 2-3 h.p porting can add another 4-5 h.p tweaking the pipe you can add 2-3 h.p.bigger carb adds a few h.p.all of this can be done and have a reliable bike.now stuff the cases shim the cyl open up the exhaust port timing add a programmable ecu you could realistically add another 15 to 18 h.p to a 250 2 stroke.it all depends how often you want to rering it.i have built some drag sleds and have had some motors built.a stock 800 triple snowmobile with almost the same bore and stroke of a 250 makes 150 h.p.porting pipes bigger carbs and ignition they are adding another 100 to 120 h.p.
Combustion efficiency
Look at banshee’s. You can add almost 30 horsepower without increasing displacement.
You can add 10+hp to 249cc no need to slow it down with a heavy piston.
Almost performs like a 250f 😆
Way more torque on the 2 stroke, and a couple more hp.
I owned a brand new 21yz250f and 96 Kx250 and rode them both for a year. Sold the 250f because it doesn't have enough torque.
Is the 250f fast? Yes, for a skinny guy on flat ground on a wide open area. Torque wins everywhere else
@@chrisvids1820 I had the KX250 97, and if your engine was like mine, it was a mid range monster. Gave me arm pump bad on the track, (but I was coming back for a few year break and probably no riding very smoothly.), but I totally loved in on 3rd,4th gear sand whooped trails.
@EarthSurferUSA yes! My 96 has alot of mid and bottom end. Sandy whoops are fun on it! I ride it pretty much everywhere from single track to MX, dunes, and desert.
I've got the suspension dialed in and it's amazing how good of a bike it is being so old. I used to think that bikes from this era kinda sucked until I learned about suspension.
A little history. Jeff Emig won MX on the 1996, and both SX and MX in 1997.
@EarthSurferUSA my next bike is either going to be a yz250 or 2018+ 250sx. I test rode the yz for a short while but never a ktm
8 HP? If it were this easy don’t you think Yamaha would already be doing this? They are competing against other manufacturers you know? Sorry dude, sounds like BS to me.
Don't you have any dirt to ride on? Stay off the streets.
Boy, are you going to be a good cop.
How much for this package ? @DirtBikeTV ?
Would rather just buy a ktm sx which already has the extra 6-8hp stock
Then you have the maintenance issues , KTM'S take more time and money to maintain .
Maybe it can keep up with the ktm’s now