Just curious as to what the on-off **** on the gas cap of my ATC125M is for?

Thanks,

Tom

 

It is a vent. Turn it "ON" when you run it. Turn it "OFF" when transporting, storing, etc. If you leave it on for long periods of time, especially during warm months, the light vapors in the gas will evaporate and eventually render the gas unusable. Once the light vapors are gone, the carb will gum up, the engine won't start and idle well, and it won't run properly if at all.

I tie a knot in the vent line on my recon and put a hemostat clamp on my dirt bike to help prevent this.