strange 2001 Warrior carb problem

profarmall · Jan 2, 2009

hi

i have a strange carb question, its a BTM carb on a 2001 warrior , it had a uni filter drop in , no lid , baffle out of stock muffler, at first we had a the stock 145 main 42-5 pilot jet, It wouldn't rpm past half throttle with out missing , like it was hittting a rev limiter, most posts said go smaller main jet , which made it run even worse. So we tryed the 147.5 changed the spark plug , it ran good for a little bit but still broke up on the big end . Tryed the 150 for shits and giggles but was too rich and still broke up on the high end . moved the needle clip down one, with the 147.5 back in , ran ok for a few then went totally rich and would hardly run. Out of frustration I pulled the airbox and just reved it with just the open carb and it ran perfect. If you try to stick anything on the carb , even just the open air box hose it misses out and loads up and runs very rich. It has a wiseco 10.25 piston, stock cam stock exhaust with no baffle .The intake is new, so no cracks in it. Anybody have any suggestions on this one? Its totally got me baffled Thanks in advance Ed

jasonp · Jan 2, 2009

Sounds like the float height might to high or the float needle might be stuck but then again you would see fuel leaking around the carb or out the vent. Are you sure it is not electrical? What is the charging voltage? I would then go to the stator and ohm it out. 2 quick things to check.
With an open airbox and exhaust like that it should not be running rich on 147.5. It also could be a intake leak. I would spray around intake carb manifold and see if the engine rpm changes.
What does the engine idle like?
Does the miss change rpm or constant as you raise the throttle?

jasonp · Jan 2, 2009

the intake boot is not deforming correct?

profarmall · Jan 4, 2009

No fuel was leaking out of the over flow. It idles and runs great, doesn't miss out, pulls through all the gears. Just with an air filter, or open piece of pipe it misses out and won't rpm. We even tryed the carb, a Mikuni VM36 round slide that came off the engine ,that I got from the guy I got the motor from. It did the same thing with 145 jets. I never thought about anything electrical. It maybe something else to check, the rest of the carb looked ok as far as float height and needle valve not sticking. Intake had no leaks but we changed that too. Still no change . Its really a fun four wheeler, just wish it had an air filter on it.

dswwarrior350 · Jan 23, 2009

PARKING BRAKE SENSOR is a good thing to toss in the trash before trying to deal with any kinda carb problem... 50% of the time the carb is fine and its that sensor that messes up. This bike should run fine with the stock jetting and these mods seeing as they are really no huge change in air intake and exhaust flow.

I'm not saying its going to jetted correctly but it shouldnt act up that bad.

Rough estimation for jetting 147.5 main, stock needle position, stock pilot, and adjust airscrew.