My youngest son has a Chinese 110cc, manufacturer is unknown, however when he is riding he can go for about 5 to 10 minutes then it will die on him. He can restart the quad and take off again for a couple of laps in my front yard and the same thing happens. I have little experience with these things. I have removed the carb and put into an Ultrasonic cleaner for 1 and a half hours, checked all pilots and jets for debris. Still having same issue. Can anyone help, I want to get this right before we go on our big ride in several weeks.

 

Are you running out of fuel? If you disconnect the fuel line going to the carburetor does it flow freely into a bucket?

I've had similar troubles in the past, and so has my neighbor. In both our cases it was a defective fuel shutoff petcock valve, but it could also be a clogged fuel filter or a clogged gas tank vent on the gas tank cap.

Let's say the fuel from the tank can only drip into the carburetor drop by drop. The float bowl in the carb fills up when the quad is off, the quad starts and runs no problem. But the fuel consumption is greater than the drip rate so the carburetor bowl eventually runs out of fuel and the quad dies. Then you wait a bit (thinking about what might be wrong) and the float bowl fills partially back up. The quad starts and the cycle repeats.

 

I am placing my bets on it being a fuel tank cap problem. I had this happen on one of my 150's. The cap needs to be vented or it will stop flowing the fuel after a bit. Verify that the cap is actually venting, usually there is a rubber diaphragm that should have a small hole in it to vent!

 

I am going to change out the fuel line tomorrow as I can see a huge difference in the size of the line going from the tank to the filter, and then it is smaller going to the carb. Could the carb not be receiving the proper amount of fuel with the difference in sizes?

 

is the huge difference in the ID or the OD of the fuel line? your carb will only pull "X" amount depending on demand. if your fuel tank ain't vented, your pulling a vacuum on the tank and after a little while, your carb can no longer pull fuel in due to the vacuum on the tank. try to find what is factory on the quad and go back with that size fuel line and make sure the tank is vented.

 

I am going to go out in the garage here shortly and spend the rest of the evening searching for that info. I will let you know what I find out.

 

OK Update for ya,

I have changed out the fuel line from tank to filter then to carb. I took it for a ride and it seems a little better. If I try to give it gas as it starts to die it will die, if I let it idle out it is fine.
I also checked the cap and can blow through it, removed the cap with limited fuel in tank and run it again, still same problem. Any other suggestions?

 

time to clean your carb and jets.........check out the float also, it may not be able to keep up with the demand if it is sticking........but it sounds like your jets are dirty/plugged.

see the small orifices? they've got to be cleaned. you need to see daylight through them and down the center of the jet....i can't stress enough how clean they need to be.