carburetor question

[rainmaker]

I recently got my first motorized bicycle running and now that the engine is broken in I wanted to try to tune the carb in a little better. I am currently running the gtx 80 keihin clone from kings motor bikes along with the reed valve that came with the carburetor. It seems to run okay but looking at the jet that came installed I can't find a single marking that indicates the size. I bought a jet kit for it but I was wondering what a common pilot and main jet size I could start with as a reference. I'm on the east coast at about sea level if that helps. I tried an 85 main and went up to a 90 but those were way to big so I went back to the one that came in it. I settled on a size 36 or 37 for the pilot but maybe that is too big as well. If anybody is on the east coast at around sea level I would love to know what jet sizes you use. Any help or advice would be greatly appreciated. Thanks alot

 

[Carl Walichnowski]

I recently got my first motorized bicycle running and now that the engine is broken in I wanted to try to tune the carb in a little better. I am currently running the gtx 80 keihin clone from kings motor bikes along with the reed valve that came with the carburetor. It seems to run okay but looking at the jet that came installed I can't find a single marking that indicates the size. I bought a jet kit for it but I was wondering what a common pilot and main jet size I could start with as a reference. I'm on the east coast at about sea level if that helps. I tried an 85 main and went up to a 90 but those were way to big so I went back to the one that came in it. I settled on a size 36 or 37 for the pilot but maybe that is too big as well. If anybody is on the east coast at around sea level I would love to know what jet sizes you use. Any help or advice would be greatly appreciated. Thanks alot

I'm in PA and I use a #67 jet size at the present moment. My carb came with a #70 I believe. I'm still tuning my carb but for me I think sizes 65-69 will work fine.

 

[rainmaker]

Thanks for the reply. The jet kit I ordered has from 70 to 90 for the main but at least I have a starting number to work with but I can always order smaller sizes if I need to. I ordered another ngk spark plug which should arrive tomorrow so I will at least have an idea if she is running rich or lean. Thanks again for your response !!