hey everyone. i just bought a mini 110cc EX from my friend. he got it off of bestpriceatvs.com but anyways something is wrong and whenever i start it it starts up at full throttle and wont turn off unless the back tires are rubbed against the ground to stop it or cut off the fuel. i dont understand how the carberator works. it has a gold about 2 inch pin that is connected to the throttle cable. the cable is connected to a black plastic piece that fits into a whole on the top of the carb then the pin goes down the middle of the plastic piece and into a tiny whole in the main intake whole of the carb. i dont know why it keeps running at full speed. could there be some other reason? help me!

 

Pictures could be helpful here...

But let's think about what could be causing the trouble.

Is the throttle stuck open? Depending on the setup of the throttle, it could be sticking open but you might not notice in the thumb lever. Take off the air cleaner/intake hose/whatever that comes into the top of the carb and make sure you can see the intake butterfly open and close properly.

You say that it dies when you put the tires on the ground. What happens when you try to start it with the wheels on the ground? Will it turn over? If you are unsure, unhook the spark plug wire and try to turn it over. Does the bike try to move when you turn it over? Could be a clutch issue.

Usually, if the clutch is working properly, it would slip instead of killing the motor...at least that is what I would expect.

Does this carb have an idle adjustment screw? If so, check to see that it is set properly.

My guess is that the throttle return spring on the carb isn't pulling it shut at idle due to either binding or breakage.

Good luck

 

well i kidna see how the carb works. there is a pin that sets in the jet that releases the fuel into the air that is sucked into the cylinder. when the pin (which sits in the black plastic piece and the throttle cable is attached to the plastic piece) agian when the throttle is pulled the pin comes up out of the hole releaseing fuel into the carb. there is an adjustment screw but i cant get it to make any difference accept then it is all the way screwed in it doesnt start. when the wheels are on the ground it starts but then dies cause of the force stopping the tires. i have messed with the fuel cut off swtich and that was made a lil difference on how long it runs. i think it all has to do with adjusting the carb. i just dont know what each thing is suppost to be adjusted to and the guy i bought it from took it apart and doesnt know much ab engines and idk if something fell out that he didnt put back in. everyhting else works. i just dont know why its constanly on full throttle every time i start it. how do i adjust it to idle only?