i have a 84 atc 110 that has been rebuilt. it will start great and idle great but when you try to rev it up it just falls flat on its face. it has no vacuum leaks the timing is perfect and the valves is ajusted perfect. i replaced the carb with a new one and ajusted it every way possible. i even tried new plugs all different brand and checked the kill switch for shorts. please help this is driving me nuts

 

Sounds like a piece of dirt in the main jet.. also, make sure you have a good supply of gas going to the carburetor.

 

i checked carb it is perfectly clean and gets fuel it still hesitates seems to run a little better when on half choke

 

Sounds like your main jet is too small. The idle jet takes care of the idle circuit, the main is what feeds the engine from off idle. When the slide needle lifts and the fuel comes up through the main and into the air flow of the carb, if the jet is too small then you will have a lean condition that will cause it to bog down and die. Somtimes it will pop or backfire when this happens. If closing the choke helps a little then you need to increase the main jet size.

 

The pilot or slow jet delivers fuel from idle till approx.1/4 throttle, needle jet 1/4 till approx. 5/8 to 3/4 then the main takes over to wide open. Running better on choke is an indicator that the pilot or slow jet is clogged. Is it a new carb. or new to you? Do you have free flowing fuel to the carb.? The screen in the petcock or the petcock itself could be clogged.

 

the carb is brand new out of the box i have checked for dirt and sprayed clean with carb clean and installed inline fuel filters fuel flows good but still hesitates

 

Did you ever adjust the carb like as in the fuel mixure screw?? That very well could be it!!

 

i have adjusted the mixture screw to factory specks and every which way i was told maybe i need a bigger main jet? because when i close the choke when i ride it it seems to almost throttle up right and doesnt hesitate. the carb is clean no dirt in it and has good flow to it

 

What jet is in it??? I can look and see what mine runs!!

 

my main jet size says 82 and i changed it to a 88 and it seems to have fixed it. it still has some slight hesitation but i am going to get some more different size jets and find the right one.