I have a few invaders. I've been riding one for years but it's beat up looking due to a crash. I had another one with an engine I rebuilt that was giving me a headache. So I pulled the engines and put the one from the beat up looking invader in the frame that is in solid condition. I will admit that I haven't changed crank seals in this engine. However, a couple of years ago I synced the carbs with no problems and have had no problem with cold starts. Typically I could get it to start on the second pull with no effort. Well after rebuilding the carbs and getting the engine back in the good frame, it gave me the same headache as the one that I rebuilt. Same problem as the rebuilt engine no start and backfires. I have a ton of br9 laying around from my former dirt bikes and sea doos that I still have. Swap plugs with the ones I used prior to pulling the engine. Bam, fires first full. So I probably pulled an engine that was fine over a bum spark plug...grr. So I get her warmed up to sync the carbs. After I hook up the homemade sync tool that I have, the clutch side pulls the fluid to the top. I've swapped carbs around and it's the same. If I pull the clutch side spark plug the engine will die but I pull the other there is no change in rpm. I've changed CDI, coil, and boots with no change.
Even though I'll hear it, I don't want to hear about crank seals, lol. If I have to pull an engine again I may just get rid of them because I have devoted to much time to these machines already. HELP!