Hello all! So I'm having some issues with a 1986 XL600R. Bike is new to me. Has an aftermarket muffler (No idea what), and factory air-box. Bike had 120 main, 115 secondary, 65 main and factory Needle settings. previous owner said he had just checked the valves and had "Drilled someone in the choke" to make it start better. It always starts on the second or third kick, runs great in neutral. Starts a little harder when hot but that's pretty normal.
The issue I'm having is that at medium throttle riding down the road it hesitates very slightly, and at high RPM in basically every gear it hesitates like its hitting a rev limiter/ loosing spark. I've checked the plug and its never looked super lean, or super rich.
Now for what I've done. Figured its got a loud aftermarket pipe on it so its probably jets. Bought a kit that came with some different jets and tried it. These were a 134 main, 130 secondary, 68 main and some shims to lift the needles a bit. This did nothing. I had as well bought a new CDI (With a higher rev limiter) and a new coil, I like being prepared. So i tried installing these. No change. I went back to original jetting, no change. I then checked the ohms through the stater for the spark circuit and the pulse ohms. Both were maybe 20 high but I'd blame that on a cheap multi-meter (But maybe I shouldn't). I also threw a adjustable spark checker and set the gap to around the 1/4 inch the manual says it should throw a spark and it seems to do that fine. It has fresh high octane fuel in it as well. So basically all I have left is to double check the valves, but it runs so well otherwise I have hard time believing that the valves are off or that the cam has jumped a tooth or something but I'm open to suggestions now!
That's all I can think of now, thanks ahead of time everyone!