ATV problem

[X-Runner]

Ive got a 250 Bear Tracker. Carb has been cleaned and rebuilt etc etc etc, no change. Nothing seems to make it better or worse. What vid for issue.


http://video.aol.com/video-detail/2001-yamaha-beartracker-carb-trouble/1651426975/?icid=VIDURVAUT09

[Me86Rob]

is it a 2 stroke? if so could be the reed valves

[Thighs]

i has no sound. whats it doing? i worked on these things for about a year, i might be able to help.

[X-Runner]

Nah 4 stroke. Back firing through the carb, also has no power/sputters past half throttle and exhaust glows red hot if you try and keep it past half throttle long.

[Barefoot]

Nah 4 stroke. Back firing through the carb, also has no power/sputters past half throttle and exhaust glows red hot if you try and keep it past half throttle long.i dont know much about carbs. what i do know is backfiring through it or a tb is normally bad timing.

[03RCode]

Could be extremely lean.

[81911SC]

How much have you screwed with it before this? Float levels too low? Causing a lean mix? Lean will make it hot as shit too.

[03RCode]

How much have you screwed with it before this? Float levels too low? Causing a lean mix? Lean will make it hot as shit too.


Tr00f. Sounds to me like bad lean, generally if its getting hot enough for the pipe to glow red, its cutting out in the mid-range, and backfiring its lean. I'd be willing to be it runs better with the choke on then off, richen it up a little and your problem should be solved.

[81911SC]

Tr00f. Sounds to me like bad lean, generally if its getting hot enough for the pipe to glow red, its cutting out in the mid-range, and backfiring its lean. I'd be willing to be it runs better with the choke on then off, richen it up a little and your problem should be solved.Yep. Adjust the float level a little higher and see what happens. You will have more fuel and could fix the possible lean issue. Like 03RCode said, witht the choke on you're kinda doing the same by adding the extra fuel. Hence why it started in the video. :goodjob:
Report back.

[03RCode]

I'm not too familiar with a beartracker carb, but you may also have an air/fuel screw on the outside of the carb, if so you may be able to fix your problem there depending on how bad it is.

[jmmx258]

Sounds like a timing issue or a bad valve, Burnt, bent, broken, etc.

Didn't watch the vid but the bear tracker is a 4 stroke, utility quad. Could be your accelerator pump if it has one. Could be not squirting fuel at all, causing it to be to lean coming off of the pilot jet.

[FasTech]

From the video, it looks like what is wrong with my little sisters four-wheeler. She has a Yamaha Kodiak. We started taking it apart and its the valve's so, that might be your problem.

[X-Runner]

The screw on the outside of the card has little to no effect. The timing is good (first thing I checked). I was also told by someone else it could be a bad valve but it runs so strong in low RPM it makes me find that harder to believe thats MY issue.

How do I adjust the float level? :thinking:

[X-Runner]

And it does run better down low with the choke pulled...

[03RCode]

Did you try seeing if it ran any better with the choke on? If its lean that will richen it up slightly, if it helps your problem will likely be a jetting or float level issue.

[X-Runner]

See the post above yours lol.

Yes it does... and why would this just start so randomly???

[03RCode]

Weather affects jetting fairly drastically if its already close to being off.

On my old bike I had to redo the jetting as soon as cold weather came around, and when it got warm again.

If its running better down low with the choke on its definitely lean.

[X-Runner]

So how do I go about fixing this then? The adjustment screw on the bottom of the carb has little effect if any.

[03RCode]

Take the carb apart and check the need position and float level. If neither of those have an affect you will need to change your main and pilot jets until you get an ideal mixture. Jetting sounds difficult, and the first few times you do it it will be frustrating. Buy a new plug (or 2) and do a plug chop on every change you make until you get it ideal.

[X-Runner]

Ive had it apart before... how do you adjust the float level or whatever? I saw no way of doing that the few times Ive had it apart for cleaning.

[03RCode]

http://www.atvriders.com/articles/jetting.html

That should be helpful.

Your needle should have different clips on it to adjust the height of it, your jets have to be replaced, you can buy a full jet kit, or if you have an idea what size you need individual jets can be found for less than a dollar.

[X-Runner]

This sucks lol. You seem to know what your talking about, want to help on day? Or someone else? I dont know how far you are.

[03RCode]

This sucks lol. You seem to know what your talking about, want to help on day? Or someone else? I dont know how far you are.


I'm all the way in Northeast GA, 10 minutes from NC. If you're not far I wouldnt mind at all helping.

[X-Runner]

I'm all the way in Northeast GA, 10 minutes from NC. If you're not far I wouldnt mind at all helping.

30 minutes south of Atlanta... :(

[03RCode]

Little bit far of a drive. Call a local shop and get a price on jetting. Shouldnt be over $20-$30, may be worth saving yourself the trouble.

[X-Runner]

Yeah one shop here said $50 or less should cover it. Think I will just let them fix it and I will put the rest back together (plastics and stuff).

[03RCode]

Yeah one shop here said $50 or less should cover it. Think I will just let them fix it and I will put the rest back together (plastics and stuff).


Would be the smart thing to do. Jetting is an art, but once you mastered it your golden. For now I believe I'd save myself the time/trouble.

[KDM>JDM]

where are you located? you said 30min south of atl...?

[X-Runner]

where are you located? you said 30min south of atl...?
Conyers...

[X-Runner]

Would be the smart thing to do. Jetting is an art, but once you mastered it your golden. For now I believe I'd save myself the time/trouble.

Its something Id like to learn but for now Im so sick of this thing its the best way to go right now.

[jfman]

There's two jets on the carb. A slow jet and a main jet.(other gearheads may have different terms for them) The main jet is that one that needle goes up and down on. The slow jet is a smaller jet that is to the side and it regulates the fuel at idle. If it's clogged then it wont idle correctly.