I have a 75 gt750 engine in and lt250f frame. The problem I am having is that when idling one cyclinder isnt firing. At 2-3k it starts firing and the bike runs great. Also when I pull the plug it has a good spark. I am thinking either the coil is bad or the condenser. What are yalls thoughts? I guess if nothing else I will try swapping condensors the try swapping coils if that doesnt change the problem. Well thanks for any help yall can give. Patrick

 

Got to be one of 2 things. I also have a good old GT750. You didnt say about the motor condition, so I am going to take a guess. Either you have low compression on one cylinder, or the pilot jet is plugged and not lighting the cylinder until a higher RPM is needed to crack open the main system. If you have spark I would look to fuel or compression. Gotta be one of them,Bubba

 

Thanks. I didnt even think to check compression. I kinda dont think its the jets. I just installed new carb kits, but I will check them anyways. I did install new condensors(auto type) and that seemed to help out a bit. I think I am gonna still try swapping coils though just to see. I had a bad points plate on it when i got it, so I wanna make sure it didnt hurt the coils. thanks Patrick

 

The only reason I say the pilot jet is that I had a twin do the same thing but would pick up the dead cylinder with a little throttle. It takes a special dial indicator to get the timing right on those machines. It goes in the plug hole and goes by actual piston location to set the spark point at. But if you have all the point gaps correct, you can time it close enough and play with it from there. With stock exhaust they dont like a lot of timing, but with good pipes you should be able to bump it some. Also up to 1mm can safely be romoved off the cylinder head without causing any problems,Bubba