again I say make sure the air/fuel passage is clear and the screw is not bent before you begin. If this doesn't fix it then your float is outta whack I already explained how to fix this earlier. Is a suck *** process
1 tweak float,
2 tweak air/fuel,
3 didn't fix it? return to step 1

but you can get it right the more I think about it the more I think I forgot to clear air/fuel passage on mine lol. This carb was horrible it took over 30 min to get the float needle out. Oh the joys of making a part you literally found both fit your bike, then make it work right. Guess it doesn't matter now since we only have about 6 hrs to live (12-21-12 prphicy lol)

 

Ok got tired of messing with the old carb, so I just ordered a new one and put it on. My problems haven't changes a bit except I could at least get it to stay running with the old carb as long as I was giving it some throttle, after I got the motor warm it would stay running at a rough idle for a few minutes. With the new carb I can't she won't come alive unless the choke is off and I give a 1/4 throttle at the right time, she will hit a link for roughly 5 seconds and die. A the factory settings are correct. I get the most response with the idle screw fully turned clockwise, air mix about 2.5 turns to the left, choke off and no air filter. She seams to want to flood easily.

 

even "new" carbs can use a cleaning. choke on = less air & more gasoline (richens the mix). keeping it running above idle with 1/4 throttle cause it won't idle w/o choke = pilot jet plugged. i don't think we're into a rev limiter issue. this still sounds like a fuel delivery issue. if it appears to be wanting to flood, take it apart and check the float/needle valve operation. have you done a vacuum test around the intake boot? does it have a flange with an O-Ring? is that facing the right way? vacuum test at boot is let the quad run and spray ether or carb cleaner in area....if it revs up, you got a vacuum leak. which would be too much air and not enough fuel.