I am working on my neighbors twister hammerhead and it has a gy6 150cc engine. It starts right up, runs fine until you put power to it, then it just stalls. I jacked it up so that the wheels are off the ground and then it takes off after a little coaxing. Put the wheels back on the ground, it stalls the moment you hit the throttle. I cleaned the carb several times, Installed a new fuel enricher, adjusted the valves all with no luck. Any suggestions?

 

Your kart should have a fuel valve on the bottom of the gas tank that is operated by vacuum. If it is clogged, not opening correctly, or if fuel is leaking back through the vacuum line attached to the carb, it will produce these symptoms. Also, if the diaphram inside the carb has a hole in it, or it did not completely seal when installing, it will also give you issues coming off idle. Good luck!

 

I did check both of these things, but I do suspect the hole in the diaphram theory. I checked for leaks several times, but I know it does not take much of a leak. The reason I suspect this is I never see the slide in the carb move. I probably should replace all vacuum lines anyway. How much vacuum should there be by the intake port where all the hoses start from, there does not seem to be much there.

 

Just an update, I replaced all the vacuum lines, and rebuilt the carb, all with no success. It still stalls the moment you touch the throttle. Could it be something internal with the motor itself, I was thinking about taking a compression test. Does anyone know what the compression should be on a 150 cc

 

i'm about to buy a quad with similar problems. i'm going to try to unplug the carb jets in case there blocked with dirt and gunk.