My son has a 90 cc Kolpin. It starts and idles fine; but dies when you put any load on it. I changed the plug, cleaned the air filter, however, it just bogs down when you try to accelerate. could the carb need adjusting/what are the adjustments?

 

It sounds to me like the carb needs to be cleaned. If it ran good at one point it shouldn't need to be re adjusted. There is alot of things it could be just start with the simplest. We clean our carb between every race, from what happens to us if it gets dirty it is going to affect off idle and midrange the most.

 

One more thing, make sure that your spark arrester isn't plugged up creating to much back presure.

 

Thanks...i cleaned the carb and added a little dry gas to the tank (we live in snow country and I think there might be a water/fuel issue). Both seemed to help alot. However, I do notice the accelartion is not very responsive. When I press the throttle, the rpms start slow and it takes a couple of seconds for the engine to respond.