Here is what i have:

97 scrambler 500 4x4 with a rebuilt cylinder, bored .40 over with new piston and rings, 150psi compression, timed correctly using the magneto& cam sproket off with gears and chain lined up method. carb cleaned several times and checked for proper operation, and good fuel.

What is does:

Starts only with the choke pulled, dies if the choke is pushed in, idles very high, will not run well past half throttle( starts to backfire) unless i let go of it.

What i need:

This thing to run correctly so i can sell it to buy another atv.

Please ask me questions so we can narrow this problem down and get her fixed!
Thank you!

 

Certainly sounds like it is not getting fuel. Are you POSITIVE you re-assembled the carb correctly? It sounds to me like your pilot jet circuit is plugged.

 

Sounds like a vacuum leak in the intake.

 

tv4fish- i never removed that part cause it looked like it was harder than handtools to remove it. the whole carb got ultrasonic cleaned and about a gallon of carb cleaner. the tech i took it to made sure i put it back together right.

overdrive- where in the intake?

 

the intake is where the carb bolts to and bolts onto the cylinder. if there is an air leak somewhere it could act like it't running extremly lean(needs more gas) who ever cleaned the carb should have removed the parts to clean them and all other passages. assuming you (someone) took out the throttle cable and choke cable did they get put back right and adjusted right? wonder if the valves are too tight? couple of ideas.

 

the choke cable was never removed. the throttle cable was removed at the carb and adjusted according to the service manual. there is also no air leak around any of the boots. I applied carb cleaner while it was running and nothing changed. Now what?!

 

i take it the carb was never taken off the bike??

 

If the choke was never remover,maybe the plunger is not sliding.

Plundger PIC

 

the carb WAS taken off the bike. i reomved the choke cable all the way up to the key panel. the plunger moves cause when i push the choke back in, it kills the bike ( feels like it starves it out of fuel)

 

a while back before my rebuild my quad would only start using the choke no matter if it was hot or cold. If i were you I`d do a compression check eventually it wouldn`t start at all.
Do you have a gas filter on the quad? if not even thou the card was cleaned crap would make it into the carb, as soon as the gas was turned back on crud would make its way into the float bowl and clog the pilot jet and maybe even the main jet causing it to run poorly.
Just a thought.