I have a 97' TRX 90 thats having problems starting. I just very recently had the carb rebuilt because it was dripping gas from the overflow. Well after the rebuild the dripping has stopped and im having problems starting. It takes alot of pulls to finally crank but once it is running it runs great! Idles nice and smooth and never skips. Its just getting it started. Im sure it might be a tuning issue but I dont know what screws to turn in what direction. I have put a brand new spark plug in too with no luck on the problem, but the plug was pretty black and it was also a new plug which I put in about a month ago. Also it seems like when its at a idle, if you suddenly (fast) go to WOT, it hesitates a tad. But if you slowly rev it up its fine.

Any help with this starting problem??? Also it seems to be alot worse if the bike if warm, like if u run it for a while then cut it off and try to crank it right back up it seems like its even harder to crank then when cold

Also since the carb rebuild I have put a good tank 1/2 through it

 

If engine has low compression it will cause an hard to crank start up...check compression 120 -150 psi. alot of time intake value willbe to tight from bad or dirty air filter..If atv has new air filter then thats an good sign filter was shot...

 

It has a brand new filter

 

Ok I would check compression of engine next step