Two-Stroke Scooter / ATV Carburetor Settings And Adjustments 4of4 : Jetting & Float Height
HTML-код
- Опубликовано: 2 окт 2024
- Part 4 of a 4 part video detailing all of the basic settings and adjustments of the carburetors found on Minarelli / Jog / 1E40QMB powered 50-90cc scooters and youth ATVs. Part 4 talks about the main jet, pilot jet, and float level. Please like the video if you found it to be helpful.
✅Tip Jar (Did this video help you?)✅
paypal.me/49cc...
#CarbTuning #MainJet #Carburetor
I’ve watched a ton of videos of people explaining how to adjust or clean carburetors. Your videos are by far the best I’ve ever seen,clear concise and well presented. Thanks and keep up the good work.
Great series for the beginners and guys like me that haven't had a carb. apart or needed to adjust because of (new air intake, exhaust, carb. re-fitment, seasons ..., ....)
Fast smooth instruction/ explanation of what and why. Camera work, lighting, audio is all great...!
Well done and thanks for reminding this old man the "whats and whys."
Thanks for the kind words.
Hey great video, where can I order (or get a part number) for that float?
I have a Bombardier DS90 here with a cracked float and I can't get parts because they're discontinued!
Need a part number for this as it looks identical!
Just replied on your other comment. Also, you can get whole carbs on eBay cheap. Search for "polaris 90 carb" and some will come up.
90GTVert thanks!
masterchaz100 : I would suggest getting a selection of main jets and doing some trial and error testing. Start maybe where your friend suggests, but try others as well and note the results to see what is working for you. I talked about this basic process for tuning in Project TaoTao Update 2 : Project TaoTao : Carb & CVT Tuning, Airbox Restriction, & Keihin PD19J Swap : 50cc Scooter It's a different scoot and a four-stroke, but the idea is the same.
When the float chamber is removed, note that there is a duct that feeds fuel into the choke tube cavity. This gets blocked with the residue that covers all the surfaces. Fuel will normally not dislodge this residue. Add thinners and or meths to the choke tube cavity and the volume above the duct and allow it to soak for an hour or until you can blow through the duct from the choke cavity. The motor will not start without the choke (enrichment device) working.
this is a great series of videos.
+Brett Swain Thanks!
2:31 are the two types of mikuni pilot jets interchangeable? or is it one style per carb?
Not interchangeable.
Got to say man, these are some of the most clear, comprehensive and informative mechanical videos I've seen on youtube. Well done! I'm a definite subscriber!
Awesome set of vids! I just picked up a little Dinli Dino 50cc, but ive never worked with 2-stroke carbs... this will help a lot!
Thank you very much,your video helped me so much.
My carburetor is a piece of crap.. the float fell into carb, the needle's spring doesn't work while the thing is upside down.
I have a kimko agility 50 400 killom runs like crap dealer says I shouldn't have to jet it can you give me some info fills like it is getting starved of gas thanks
Very good explanation. ❤
Thanks for sharing a wonderful video. 💝💐
Great vedeo on carb rebuilding and maintenance thank you
Which way do you bend the tab that the needle sits on for for or less fuel?
I have a question... I know it's been 12 years since the video is posted but my Malaguti F10 Jetline is having some problems. I bought new parts for it like new carburetor, cylinder, piston, variator kit... everything is new on my scooter. Tried everything you showed in the 4 videos on how to but when I drive it, it goes very very slow up in speed and uphill it's slow af barely goes to 10mph. I don't know what to check. I checked the exhaust, the intake, generator, sparkplug, sparkplug wire, cdi, even new battery... It's my second Malaguti F10 and with the first one I could go 50mph and this one barely makes it to 25mph on a downhill.
Cover the basics first. Do a compression test, check spark strength (bend the ground strap way back on an old plug so it has a big gap and make sure it still sparks bright and consistent), double check the air filter, air box, intake connections, fuel supply. Try using known good parts off of the well performing scoot (CDI).
So i have Baotian aprilia sr50 replica when i start it up the idle is around 1800rpm then when i drive it and its warmed up ti goes up to 3000-3100rpm and stays there, should i re-adjust the idle then ? or something is wrong with my carb?
Crepsitto Try readjusting the mixture screw and speed when it's warm. You may have to compromise between the best cold and hot idle quality or decide which is most important to you.
Def go up on the pilot if you need the screw almost closing the passage to work. Now I'm more confused because the pitbike engines I was thinking of should be four-strokes, not 2Ts with reed valves.
Hi man. Do you know of a link where i can buy that rubber seal on the bowl? Mine broke off when i cleaned the carb. I hve a stock mikuni carb that has number 16-56829 written on the outside of the carb. Thanks I'm from NZ usually gets my parts from ali express
Look up the scooter places that you normally shop or places that ship globally like maybe scooter-attack or scootertuning. In a pinch, I have measured o-ring diameter and then figured out it's size if round and found generic o-rings that work. That can be a pain when the ring has a lot of contours beyond the basic round or rounded rectangular stuff though.
My god I feel dumb. So the main jet isn't supposed to be loose at all? Been having an issue with my old moped and I have the main jet loosened a bit because that's what I thought it was supposed to be. Well, I guess I can check if that fixes it tomorrow. If so, many thanks!
No. It should be snug. Hope that fixes it.
hi hope you can help. I have a piaggo zip 50 2t 2stroke scooter. I done the idle and mix adjustments as in your last videos. the problem is its seams to have more power just off full throttle. if I back off ever so slightly it runs great when I go full throttle it feals like it bogs down a bit and dosnt want to rev right out like it use to. any thoughts?
Try using a larger main jet.
I would get a main jet kit. For the pilot, try richening the mixture screw first. When I search it appears that what you have is a pitbike/trailbike type of engine. Been awhile since I've worked on them to know what they like.
Took carb off 90 cc 4 wheeler and cleaned carb and jets throttle snaps back as it should but throttle seems to stick when I'm going full speed and go to let off and it's still wanting to go on it's on
Could be a cable issue or the throttle itself. You'll need to inspect the whole system and it wouldn't be a bad idea to lube the cable while you're at it. Replace the cable if you find it frayed anywhere.
Legend, my lx50 gonna be purring
Very informative videos . Only thing I can say is between vid 3 and 4 I wish he explained more on what problems or out comes you would see with the main jets and or the needle jets
i just upgrade to 44mm piston, what size of main jet would you recommend? Thanks
I always recommend getting a jet kit and going through a tuning process. It's not the easy answer that people usually like, but it's the way to get it in tune.
Do you use the carberutor used in this video for your 80cc performance scooter? I have the same one and have a 70cc kit with a air pod filter. I am at a #115 main jet and for the life of me cannot get it rich enough to bog at all. Any suggestions?
My 86cc that's currently in my scoot is way too much for a stock carb. The stock carb has worked fine for me on mild 70cc builds. It is even OK with a stock 90cc, though the 90cc ran much cooler with larger aftermarket carbs for me.
My first suggestion would be to go back to an airbox and go through the main jet selection process again. I'm using a modified stock airbox on my 86cc at 14,000RPM with a 25mm carb.
ruclips.net/video/SJth-GEy9aY/видео.html
Sir, I have a problem
My motorcycle consume a lot of gasoline in short distance
Are there solutions
and Thank you
So if i want my stock airbox with snorkel off to a ppd filter i would only have to upjet the pilot jet?thanks
Main jet almost certainly and maybe the pilot jet. If you can get the tune at very low throttle right with the idle mix screw, than you won't have to change the pilot.
Really good explanation, thanks
Got a question see my quad it bogs down when i full throttle it what would it be i have cleanes the carb and bypassed the fuel tap amd still it bogs
I was looking few Days for Good tune video and i finaly got it! Thank u so much :)
First clean the carb thoroughly. Check for intake leaks.
This video set helped me troubleshoot the carb on my boys predator 90 and get it running like a top. Thanks 😊 🙏
Both jets sound small to me with an open filter especially. Maybe go back to stock airbox till you get some jets.
I need help my carb is leaking after every ride for few minutes and it stops from overflow and i tested tension on my float and its super good but it doesnt stop leaking
If the float height is good and the float isn't stuck, then maybe the float needle isn't sealing off flow.
great vids maybe you can help my Yamaha.. 99 razz riva, manual choke, idles fine bogs down when you hit the gas and dies, gas leaking from air filter, I replaced the petcock but still leaking slightly.... cleaned the carb and float seems to be working, I blew air into it and the flow stops when the float is lifted...ideas? maybe I messed up the adjustment screws when I put it back together.. set mix screw at 1 3/4 turns from bottom out, idle screw just above the speed to get the back wheel spinning (5 to 800 rpm Id guess)
Float height may still be wrong. If it's leaking fuel from the airbox, that's usually a float issue. Till you get that solved, you won't be able to get a good tune.
Thanks for your explanation.My bike Yamaha FZR 250. i cleaned my mikuni
carburator (4) and cleaned main jet,pilot jet and adjust air mixture 2.5
turns out from the closing point.Cleaned the air filter.My problem is 3 times failed my eco
(smoke) test and result show more petrol consumption.but last years
easily pass the eco(smoke) test.My problem is need to reduce petrol.How can i
adjust/reduce petrol flow ?please help.Thank
+Ravi Shane Make sure the engine and emissions are in good working order. I don't have emissions tests here and don't know anything about smoke testing. If something specific like NOX or CO emissions are the issue, changing mixture may help. A little more info on that here : www.49ccscoot.com/faq/richorlean.html
I'm installing a yz80 carb on my 70cc vino 2 stroke, I want to relocate carb is there any problem with making intake a foot long?
Generally people are trying to get a short inlet path and the most direct flow toward the transfers. A long intake may make the engine favor low RPM. In the case of a foot long intake, probably very low... like idle.
@@49ccscoot thanks pal
sir~ I have PHVA 17.5 carb, my friend said that 0.75 mikuni idle jet are able to replace.
but vm's thread diameter are too big for my carb
orignial idle jet Screw thread size=3.9mm*0.75
VM16 idle jet Screw thread size=4mm *0.75
I couldn't find the right idle jet to replace...
You can get PHVA idle jets from treatland.tv and prob other places.
What’s the model number of that carburetor
It's similar to a Mikuni VM16. I don't know of a model number from it. It is from a Chinese scooter.
Hello, Frist thank you for all the videos. I have one question. I was change cylinder with a little more powerful and now I have problem with the power. I think that don't get enough gas. So now I need to change the jet, but I don't know which jet, main or pilot jet ? Thank you for answer.
Could be any of the jets or adjustments, but most commonly it's the main jet. Helps to understand what works where. www.49ccscoot.com/faq/carbtune.html
Hey B, just curious. What is the big silver bolt sitting above the idle screw(edit:speed). I know it's not the AF screw, but just wanted to know since my carb has one aswell.
Simple answer : Nothing you need to worry about.
I'm not totally sure. Most of my carbs don't have that. It isn't any sort of adjustment. It seems there's an extra fitting on that carb for some reason and I guess they stuck a bolt in there.
hi, I have an aprilia rs 50, which i put a 70cc kit on, everything was running fine until i bought an aftermarket 21mm carb (originally 12mm) I also bought a new open air filter which is extremely pourous, now I don't know what to do with the jets (90 main and 60 idle), I'm not sure whether it needs to upjet or downjet, its rather boggy (only doesn't bog when WOT in 3rd,4th,5th and 6th gear only WOT), should i buy bigger jets? (there is quite a bit of smoke no matter where the needle is) Thanks
i just got a stage6 delorto 21 carburetor and i install when i put my throttle to the max it go 30kmh and not faster but its supost to go like 90kmh do you know why is doing this ?
What do you call those clips that are holding the fuel and vacuum hoses on in your video? What is the size of the fuel hose for that carburetor (1/4"??) Where can I order some? I'm in the middle of nowhere. Thanks.
I'm getting fuel into the bowl of the carburetor, however I am not getting any fuel to come up into the tunnel where it should be mixing with the air. My scooter stopped running last fall and nothing would have been changed on the carburetor until I just took it off and cleaned it out. Do you have any suggestions to trouble shoot this?
Make sure the main jet and atomizer is clear. I would go over the carb again and be sure you get every passage you see with carb cleaner and compressed air. Sometimes you can hold your hand over the mouth of the carb to choke it while you crank the engine and that will be enough to get it to start moving fuel.
hey i have a 90cc extreme machiinee which is same the eton 90 i beleive but it will idle fine but when i go to give it gas it just dies ive cleaned carb couple times im lm lost what to doo
I adjusted my idle with the idle sreww and i noticed when i was in traffic with my bws 2005 it was moving on it owe when i did not apply the breaks. a few lights after as i was slowing down the bike shut off. i went to kickstart it but the kickstart would not move. i thought my belt broke. i opened it up and the belt was fine but the drive shaft had a one turn play to the right and left then stop dead. can you tell me what damage would stop a driveshaft from moving freely?
If all the CVT stuff is off and the driveshaft turns, then locks, either the brake is locking up (maybe a high spot on a shoe) or something is wrong inside of the gearbox.
Yes the Chappy LB50 is along the lines of a pit / trail bike. Has reed valves. So currently main is a 70, are you saying to go up on the main jet - like 90 or 100? Wouldn't I want to go up on the pilot jet size also? The current pilot is a 15 and is set at 1.5 turns now, any richer will close it all the way. Initially you said both jets sounded small to you, especially with open filter and exhaust.
So if i do as you say in these videos and use my head as well i should be fine?
Grenaded my 124cc malossi cylinder when i tried to tune it myself....
Thanks for the info!
...And remember that if you aren't sure, err on the side of rich.
I have a alpha sport 50cc atv which is the same motor as the eton 50 polairs predator 50 and more but the air mix is set at 1/4 turn out from seat and i go out more it revs higher and dont drop. and when rode it takes off slow and half throttle it loses power like bogs.. you think the main and piolet jets are to small.. no air leaks..
I have 100 jet in my moped its got a k&n air filter and a pm tuning 360 pipe and it bogs i was wondering what size would I need and whether it needs upjetting it a 50cc gilera
Oh and I recently fitted a new not kit only a 50cc one but would it still need upjetting my friend said i will need to go up by about 10 so I would need around a 110 main jet. The 100 jet runner fine on my old bore kit which was a 50cc one two and I had all the same parts on it as I do now i just don't understand why it's bogging down at half throttle I would easily get 55mph out of it now i only get 20 to 25 if I'm lucky and it bogs before I get to that sometimes so please help?
Help !!! I have a Eton Viper 90R that idles great but when you give it gas it bogs down. Any help with this problem will be greatly appreciated
My first two steps would be to ensure that the air box is installed and in good condition and then to make sure the carburetor is clean and jets are clear.
Do you know what model is that mikuni carb?
It's at least very similar to a VM16. Not sure of anything more exact than that. It was stock on a Chinese scooter.
Hi tks again four you post your good video, my scooter the petrol not came out from tank to carburettor is lucke the float problem because I thing is the vacuum pump I by a new one and fit and still not petrol came out the carburettor I cleane before the carburettor and I remove the float probley I not fix correct tank you Berenguer
Take the carb out of the equation. Totally unhook it and crank the engine over. Fuel should start coming out of the fuel hose. If not, something is clogged, malfunctioning, or not connected properly. Check all hoses for cracks and leaks and recheck routing. Make sure the inline or in-tank filters are not clogged. Try removing the fuel cap and seeing if that changes anything.
i'm having problems with my aprilia sx 50 i purchased a new exhoust put it on there and can't get it to accelerate very well if i let it idle and give it gas it goes but stutters on high revs on low revs its having trouble i tried alot of main jets i'm gonna try to put the needle in the right place and hope for the best
Once you get a pipe, make sure you keep the revs up as it's likely to be kind of dead at low RPM. Stuttering/sputtering is usually rich, but looking at your plug after a WOT run should confirm or deny that.
ya jets are all clean like i took my time and i have the air box installed nut no snorkle but the filter its self is there i just dont have snorkle
whats the best jet to use for piaggio typhoon 80cc carburetor
excellent vids. learned a whole lot. Quick question. Is there anyway of adjusting the oil? how do we know that it is mixing correctly? Are there jets?
Thank you!
Thanks. Some pumps have adjustments :
49ccscoot.proboards.com/thread/3151/avoiding-soft-seize-pump-adjustment
OK I get what you're saying, but no this is a 2 stroke, single, with 2 reed valves. All Yamaha Chappys are like that and came in 80cc or 50cc. The 50cc bikes (like mine is) were designed as mopeds.
When I apply throttle it kills my CPI SM 50 which i have this carb on as stock.. Can you suggest anyways i can make it work? If i rev really slowly itll catch and i can use it fine until i stop again.. and i cant be doing that all the time at traffic lights etc.. Thanks!!
How do you know if its an m4 m5 or m6 threaded jet?
The thread is 3mm in diameter, and the head is 5mm diameter.
The diameter of the threads will tell you. So, and M4 is roughly 4mm... usually a little shy of 4mm... but not 3mm. You can also use thread gauges, or go to sites that have measurements of jets and try to match them up. JetsRUs has some measurements.
@@49ccscoot thank you!
This helped alot i cchanged the jet of my speedfight 3 but now i have installed a race air filter i have to close air screw all the way off! bigger jet? or need to adjust my carb? thanks you deserve more subs!
Best carb videos I've found. Well done.
Ah ty for the quick reply! Would it also help to turn the idle mixture screw counter-clockwise to lean out the mixture? My scooter has worked fine in the past it's only been doing this the past week.
Awesome vids and crystal clear direction! I have a Chappy LB50 that I put a 70cc kit on, that won't start. Carb is stock, Main Jet 70, Pilot Air Jet 15. Air and Idle screws are set at factory spec. Carb is squeaky-clean, all passages clear...can even see light thru them and thru the jets. I have a clamp-on hi-flo air filter. Spark is good. Compression good. Stock exhaust has been hollowed out, and the baffle removed. Do I need to go up on Pilot Air Jet size??
Thanks for the video, I just bought a Genuine Buddy 50cc, and want to get some more speed out if it. So I’m looking at the Prima exhaust upgrade that comes with the jets. Dealer wants $300.00 to install. I Never changed jets out of a carburetor before, thanks to you, I can see it’s very easy. Thanks again 😁
Good luck with it! Way more info if you want it : www.49ccscoot.com/faq/carbtune.html
@@49ccscoot Thanks for the further info. About to do a new main jet on a 2020 Taotao pony 49cc scooter carburetor.Was trying to see my best starting point.Definitely going the 5-sz. over & rich.Then back it down as tread talks about. Thanks alot!
Hi again my 17.5 carburettor have a problem i order a new one 19mm you thing the air pipe can fit thank you again
Depends on the carb, because there are lots of variations of 19mm carbs. Many can be made to fit. I've used 19-21mm DellOrto PHBGs in stock intakes a lot.
Is same this one item number 203299831261 EBay thank you PiaggioZip 50 2T
@@MrBerenguer67 0 results for that number. If it's for a stock scooter, it may fit. See if the listing has any dimensions that you can check or try asking the seller.
Hey! Do you know why when the idle is not stable ? Currently ride Yamaha 2stroke. @90gtvert
Question. When I change the main jet, do I also need to adjust the position of the needle or do I leave it as it was? Thanks
Just answered this on the other vid where you commented. Short answer, no.
Hi do you have any idea where I can get different jets I have issues with the main mix screw being screwed near shut for quad to run right
JetsRUs, PartsForScooters, Amazon, eBay
If it's the carb shown in the video they're Mikuni VM11/22 main jets.
Top guy for sharing this . excellent description of Cab settings and how to dismantle them .. You are the man .. Thanks
Thanks!
Thank you! Exactly what I was looking for!!
Best video so far thanks for explaining
great video, thanks man
hey, i have keihin carburetor in my scooter, and im not getting any fuel there anymore. i checked this, and i had no yellow thing where my float needle goes, so am i missing some parts? sorry for my bad english hope you know what i mean? thx if you can reply!
If anything were missing at the seat of the float needle, it'd be more likely to overflow fuel from not sealing. Check float height and make sure the petcock is working and nothing is clogged from tank to carb. If the carb has fuel in it but it never makes it to the engine, clean the carb.
***** okay, thanks for advice. but when i take my float bowl off, there goes gas, but when i put it back, there goes no gas. well il check all those things. thanks :)
***** btw, i dont have petcock, i have automatic gas bumb there?
*****
Since it fills with gas, the pump/petcock should be working. It's getting fuel to the carb, so clean the carb thoroughly. Get all passages with carb cleaner and compressed air and make sure all of your jets are clear.
my carb is exactly the same.. mine is a mikuni and its written jet100 on it.
Hi , your videos are excellent. Keep up the good work!
I have a CPI GTR 50 with a mikuni VM16 with 17.5 pilot jet and I'm not sure that is the stock size. Do you know the stock size?
Thanks
Beniiito69 Thanks. The stock carbs I've had have been 17.5 - 22.5.
***** OK thanks!
Super thank you
I have an 04 zuma. when I got the scooter it ran fine, fired right up no issues. after having it a little while I noticed it was leaking from the overflow on the bowl. I replaced the valve needle, cleaned the valve seat and replaced the bowl gasket. doesn't leak anymore but now is a p.i.t.a to start. I adjusted the air/fuel screw and best idle was with the thing almost all the way out. I also replaced the air filter with an oem replacement from uni and may have over oiled it? the old air filter was completely disintegrated. was going to order a smaller pilot jet but I'd like your opinion first if you can help me out. last thing, after I get it started (about 30 seconds on the electric start) it runs great down the street and fires back up instantly.
My first step would be to take a look at the air filter and clean and re-oil it if it's over oiled. See if the enricher is working. Check your float height. If that's good, you can try a smaller pilot jet.
90GTVert Thanks for the reply!
wow you rock teaching man,you make that shit look very simple .
Funny you should say...I'm shopping jets now, any suggestions for a Main / Pilot?
i have an issue with my tgb 101s where it just loses all its go at around 30km/h. kinds seems like it isn't getting enough fuel. I haven't got a machanical bone in my body... any tips on what i can do?
A really common issue is people changing air filters or modifying/removing the airbox without rejetting. If any of those things have happened, go back to stock or rejet. Look for air leaks, like a cracked intake or damaged vacuum hose.
+90GTVert I have a feeling the air filter isn't stock. i only just bought it. the current air filter is just sitting there not in a box not fastened in any way. didn't notice until after i bought it.
and now its the first tutorial i understand about carbs
hello i have a problem my bike bogs at 1/4 throttle, it runs great at 2/4 to full throttle
You can try richening the mixture screw first. See if it improves. If not, try leaning it a little bit. Make notes of where it was and how much you adjusted, so if it gets very bad you can at least get back to where it is.
That may not solve it, but it would be the first thing that I'd try. Then maybe try richening the needle one clip position and see what happens, if it doesn't run well with just the mixture screw change.
@@49ccscoot thank you for fast reply,
i tryed richening mixture and it was most stable when it was totaly screwed but i had problem with stuttering at full throttle, solved problem by raising the needle to the max, but now i have problem at full throttle mixture is too rich it doesnt stutter but its worse i can feel it i will try smaller main jet tommorow
@ Sounds like you're on the right track.
I need this exact o'ring for the float bowl on this carb but for some reason I can't find a picture of it when searching to buy one. Can anyone help with a link that shows this exact o' ring I would really appreciate it. Thanks!
ah just found one on ebay $2.50 - $7.50 shipping... or for $23 bucks can get a whole new carb!
It doesn't often pay to rebuild generic carbs. Tune 'em and clean 'em, but if they need many parts consider replacing the entire carburetor.
Could you help me about needle clips
Does this help?
ruclips.net/video/KXxxJrA5hNY/видео.htmlsi=OpJ8rAzVIiebp4cA
Can you give me a tip on where to get one of these? I have an Adly blazer 90 with the same carb.
I have an Eton Beamer all stock but I just ordered my 70cc kit to go on it. It has the stock exhaust pipe. Should I replace the jet? If so, 1 or both jets?
Also what kind of pipe should I get? I have heard if you just put a bigger kit on without rejeting, it will freeze up because it is not getting oil needed for the bigger jug. Any help would be appreciated.
Thanks!
Most likely you'll be fine with just a main jet swap. Fuel helps to cool the cylinder as well. If you run a two-stroke lean it tends to heat up and soft seize (the piston expands more quickly than the bore). What pipe depends on what kit and what you want, but for the average sport/street big bore kit a Leo Vince ZX is a good choice. If you want something more quiet or for a little better low end you could try a Leo Vince GP or SP3. There are other good pipes, but the Leo Vince stuff is pretty good quality and works pretty well.
What size main jet should I get? Also what kind of pipe will get me the best top end speed? Thanks for your rapid response.
TubeRadioSaver
I would get a main jet kit and tune it rather than hope 1 jet that anyone chooses works. www.partsforscooters.com/?partner=49CCSCOOT and others sell them.
The MRP pipe did the best of the ones I tried with a tuned cylinder, but I think the ZX is a good choice if you don't want to do porting and lots of CVT work to keep it on the pipe. Still you'll probably want 1500-2000RPM clutch springs for the LV ZX.
Hey my brother! Love your videos they are very informative. Even though I ride my two stroke every day, after it has been sitting for more than an hour, there is TONS of white smoke coming out of the exhaust when i start it back up. I look like a mosquito truck going down the road haha. It clears up after like 10 min of running but I'm not really sure how to prevent it from happening in the first place.
great vids, realy usefull. already been bussy with my quad, different carb, a dellorto 17.5 tho. had a main jet that was to large so would not go faster than aprox 30km/u. now it reaches about 45 or 50 which is just right and runs nicely, but when it is on operating temp it does not pull good anymore. the first bit when idling an hitting wot goes fine but then it slowly climbs in speed, where before it would realy pull. so u could say i am missing torque
Also consider the CVT. Sometimes springs fade with heat. CVT gets hot and RPM drops. Watch your tach carefully.
@@49ccscoot nice of you to reply thanks :) i wip have a look and check the condition, but other than that how would i know that it is the cvt, and not a lack of fuel or something? the sparkplug looks oke, a bit mat black even but i dont dare going smaller with the main jet, afraid it wil run to lean. also i moved the needle clip 1 position down but that seems to make it worse
@@Kpostma100 The tune for the carb really shouldn't change much from warmed up to a little warmer than usual. If it's heating up a bit too much, that may tell you it's already too lean or there's an issue with cooling otherwise. With one of my scoots, it was pretty obvious. I had a CHT gauge and that would stay about the same and also had an oil temp gauge on it (four-stroke), and after time it would drop RPM. Without seeing engine temps rise, it was easy to tell that something else had to be happening.
Thanks for the vids. I'm trying to get my son's "new" 2005 Polaris Predator 90 going. Got a new carb. Got idle and 0 ~ 25% throttle running like a champ based on your advice. Still bogs down above 50% throttle and will die if left there. No air filter attached to carburetor to rule that out. Any suggestions?
With the airbox off they will run lean and bog out, so make sure the filter element inside is clean and then do your diagnosis with the airbox installed.
***** Thank you! Got it going. Put the airbox + filter back on an in the process learned that I had the choke on the whole time. I'll stick to my day job and leave mechanic'ing up to the pros. :-)
Glad you got it running.
Hello 90GTVert , i am having a slight problem , i have changed the air filter , exhaust and am trying to change carb on my yamaha zuma 50cc , but carb cable isn't the right one ( i am trying to install Dellorto 17.5 ) , Dellorto is using cable such as in your vids here when you showed about needle , but mine cable end is different , should i change the whole throttle handle with cable , or is it possible to change only cable ? Thanks !( sorry for bad english )
I think Motion Pro (I could be wrong on the brand) makes a Zuma specific cable. Some of the Zuma guys on my forum could tell you if you can't find a specific cable.
I don't need to change the handle ? only cable right ? and still , thanks ~ !
If I'm correct on that cable, then yes the cable should be all that you'd need to swap.
i am not sure but your mainjet looks not really to fit pretty long the screw thread
It is the proper jet. The one you see is the jet that came stock in the carb. The VM11/22 jets have worked for me for the last 10 years in these carbs and match up to stock well, so I think they're OK.
okay thank u
Mine tried to die at full throttle :( but at 1/2 throttle it keeps accelerating
Might need a different main jet.
Great video. I've got a carb off a 2000 Scarabeo 50 2T that I've been struggling with. The float doesn't have a metal tab on it that you show here and what I've seen on every other type of carb I've ever seen. This one instead is fully plastic and the needle valve is connected to the float with a spring. With the carb inverted the float seems to be resting way to high(i.e. setting down into the carb when upside down instead of level). However since the whole float is plastic there's no adjustment that I can see to make. Does this style of carb sound familiar? Could it be that spring that holds the needle valve is worn out? If not then is it OK for this style of carb to to not necessarily rest level to the bowl mounting plate?
It sounds like maybe the spring is worn out, but I can't find any Aprilia Scarabeo service manuals for any specs. If it's not having any overfueling issues, maybe it will be alright. Perhaps you could go to a hardware store and find a spring that would work to get it level when uncompressed.
Thanks for the reply. Would overfueling cause the engine to sputter? That's what appears to be happening after it warms up. For the first couple minutes it revs up fine, but then consistently it just starts to sputter and cant get enough RPMs to accelerate beyond a crawl. I originally thought it was a breathing issue but everythign's clean. The float kit is only $10 so I went ahead and ordered it anyway just in case but curious to know if what I'm describing is symptomatic of this issue.
Rich conditions do cause a sputter and also the plug will usually look wet at that point if you check it. Could be a faulty enricher or not getting power to the enricher. The enricher adds fuel for a few minutes at startup, but should stop automatically. If it doesn't work, it can cause what you described. It should be retracted when cold and then once the scooter runs and it gets power it will heat up and expand to block off a fuel passage. Vid below shows it working out of the scoot.
Automatic Enricher Operation (10x Speed) : Choke Bypass Bystarter
What is the size of that mainjet ?
As far as orifice size; I'm not sure. It's been awhile. Most were 55-75 range. Thread size is 6mm and DellOrto 6mm main jets worked for me as well.
Great video. I really needed the part you worked on the float needle valve. Thanks again!
I can't understand what's going on with my 1982 urban express deluxe, it hits 20 then sputters... How do I fix it it's all stock with an 85 jet
Carb cleaning and checking the condition of the air filter and airbox would be at the top of my list.
90GTVert air box is good carbs clean main jet is clear
Is the 85 main jet also stock or a recent addition? If that's a recent upjet, it could be the issue. You may also want to make sure you have a strong spark. Use an HEI or adjustable gap spark tester... or bend back the ground strap on an old plug or cut the ground strap off totally and that makes a big gap for the spark to jump. Alternatively, you could try decreasing plug gap by around 10 thousandths and if the issue goes away, you either had the plug gapped wrong before or the ignition system is weak.
90GTVert 85 is stock what im running