I'm working on a cb500t and am having a few issues with the left cyl only firing when the throttle is applied, or the bike is above 2500 rpm. Picked the bike up with 12k on the clock. Was an okay runner but had an issue with firing on the left cyl. I picked it up pretty cheap so I figured I'd be fine spending a bit to get things like I want them. Swapped the carbs with mikuni vm 34s with 180 mains. The carbs were built specially for the Cb450t and 500t. That being said...I know the carbs aren't the issue. It has a new battery, new rectifier, and the harness is completely intact. At idle the engine not only sounds like it is only firing the right side, but it also vibrates more, and the left header is cold. At around quarter throttle and above the right starts to fire like it should. Should I suspect the coil, the plugs, or the points? Any ideas are helpful.