01 bear tracker 250..not getting enough fuel?

[ssupercoolss]

picked up a bear tracker cheap, with some issues. it was running away, popping, and had to keep the choke on, etc....took the carb off, cleaned it up, now its running much better. sort of. now is seems as though it is getting way too much air, or not enough fuel. i have the adjustment screw turned out more turns than i like to admit. messing around with things a bit i took the air filter out, and partially blocked the intake with duct tape, which in turn makes it run much better. missing a little punch off the line, but not totally bogging out. any ideas here? i dont claim to be the carb king, but this seems to be the most complex carb i have seen in a while.

[ATVmechanic]

You said that you cleaned the carb...have you taken it apart and inspected the components like the float...Sounds like it needs to be rebuilt.

[ssupercoolss]

i did actually inspect, everything looked ok, but i am still strying to understand how that carb works. i dont understand that whole vacuum slide thingy. i did order a rebuild kit, even though things look pretty good inside, but who knows what the PO was doing in there. is there an adjustment on the needle itself?

[ATVmechanic]

Take a look at the diagram here: 2001 Yamaha ATV Parts for BEAR TRACKER / YFM250XN, Fuel & Air - CARBURETOR

There are a few adjustments that can be made.

[DirtDemon]

On most carbs, there are five spots for the cirlip on the needle. Move the clip down to richen, up to make it lean. However, I couldn't see any grooves on the needle in the diagram. So?? At any rate, I would rebuild the carb and make extra sure that you have cleaned out EVERY little orifice in the carb and go from there. Check the floats and the fuel lines/petcock as well.

[ssupercoolss]

i am giving up on the carb being the problem...for right now. i have taken it apart 3 times, moved the needle onto every position (3). with any adjustment, there has been no change on how it runs. i need to start looking into the rev limiter, cdi, parking brake switch...etc. currently the parking brake switch is unhooked, but i still think the cdi is getting a signal that it is engaged. hopefully i can test the cdi, and not just blindly put another one on. one would have to assume that one of the wires going into the cdi is a ground triggering the rev limiter. at this point i just cant figure out which wire it is.

[Ajmboy]

I think you have carb issues, although maybe you do have an issue with that cdi. Generally, the first thing to check is the carb. Possible causes are:

Main jet clogged or wrong size

Jet needle or needle jet worn

Fuel level in carburetor float bowl too high or too low

Air cleaner clogged, poorly sealed, or missing

Air cleaner duct poorly sealed

I saw your post on this site: bear tracker, cdi? rev limiter? - ATVConnection.com ATV Enthusiast Community

What site will provide an answer first???....LOL...

[ssupercoolss]

clearly i am no genuis when it comes to carbs. but the definition of insanity is doing the same thing over and over again expecting different results. seems like i could pull the carb apart 10 more times and i think i would have the same results. i would be willing to bet at this time either the cdi is bad, or it thinks the parking brake is on.

[Ajmboy]

clearly i am no genuis when it comes to carbs. but the definition of insanity is doing the same thing over and over again expecting different results. seems like i could pull the carb apart 10 more times and i think i would have the same results. i would be willing to bet at this time either the cdi is bad, or it thinks the parking brake is on.

Hmm..does this atv have a feature where it will start in gear if you depress the parking brake? If so, is it starting in gear without depressing? Or not starting with it depressed?

[ssupercoolss]

Hmm..does this atv have a feature where it will start in gear if you depress the parking brake? If so, is it starting in gear without depressing? Or not starting with it depressed?

it does have that feature. and it is working as it should, although i currently have it disconnected. the thing i am struggling with is both wires going to the parking brake switch go to ground when tested with a test light. that seems odd to me, you would think one would be always grounded, and the other become grounded when the parking brake is activated. my thought is something beyond the parking brake switch is causing this to send the cdi into rev limiter mode. i just cant figure out what yet.

i guess one thing i did neglect to mention is that when i was tring to adjust the carb, i did grab the brake, to see if it made it run worse.....and it didnt make it run any different. thats kind of how i decided to stop fooling with the carb, and explore other reasons.

[ssupercoolss]

problem has been fixed. not positive what i did, the last thing i did was disconnect and reconnect the plug on the rectifier. so, it was some type of electrical issue. once the electrical issue was solved i put the needle back on the middle clip and it will do wheelies. glad i quit fooling with the carb and looked for other reasons for the problem.

[DirtDemon]

Good to hear, ride on my friend.