Motorcycle Repair: Idle Problem, honda 110, houseofmotorcycles

Question
Hi I own a 1985 Honda 110 atc that i just bought. I am having problems with the idle. When at idle the machine will rev up high for a while and then idle down low for a while and then die out. In order to maintain a good idle your hand has to be on the throttle of it will die. During normal driving conditions in gear it will run fine. I noticed that the seal that seperates the upper and lower carb is leaking for your information. I have tryed to lightly adjust the idle screw but that doesnt help much. Please help me out with this problem. THANKS

Answer
Tyler,

-it sounds like the carb is in need of service.
It may have water or dirt blocking a jet or air passage.
Also the float valve may need cleaning, adjustment
or replacement. That is the part that keeps the
fuel level at the proper height in the carb
bottom bowl. The carb bowl also has a gasket
or o-ring where you saw the leak.

-the slide in the top of the carb may be sticky
or maybe the throttle cable is stiff.

-The o-rings and gaskets where the carb attaches
need to seal well and prevent air leaks.
-the carb has a filter in the bottom that
needs to be clean.

-valve clearance may be tight, should be
set to .004" clearance when the flywheel
is on the "T" mark, engine on compression.

-fuel petcock valve also has a filter screen in bottom to clean.

A good carb cleaning may help your problem, check that the
float valve is able to stop the fuel flow
when the float pushes up on the needle valve.
This diagram may help:
http://houseofmotorcycles.bikebandit.com/parts/Honda/ATC110/1985/169043
float valve is #13
idle jet is #31