The choke does 2 things. It makes the mixture richer with more gas, and it also raises the idle speed. Try adjusting the mixture. If it has no effect, the idle circuit in the carb is plugged and needs cleaning. If it helps, then you probably have an intake leak somewhere. If it is just the idle speed that matters, then try just increasing the idle speed adjustment, or make sure the plug is not fouled or anything else that could make it run bad.
Answers & Comments
The choke does 2 things. It makes the mixture richer with more gas, and it also raises the idle speed.
Try adjusting the mixture. If it has no effect, the idle circuit in the carb is plugged and needs cleaning.
If it helps, then you probably have an intake leak somewhere.
If it is just the idle speed that matters, then try just increasing the idle speed adjustment, or make sure the plug is not fouled or anything else that could make it run bad.
How do you clean the idle jet?