So I recently picked up an XL600 and it's been nothing but a big dirty headache... I'm not new to fixing bikes/small engines, but this one has/keeps me stumped. I'll start at the beginning...
I picked it up with a dirty tick in the top end, took it apart and the cam chain was notchy/stretched and one of the cam chain guides was pooched. I replaced these, lapped the valves, cleaned the carbs, and reassembled. The bike fired right up when I got it back together, and ran well... until I shut it off and tried to restart. It would not start from hot. I've done many carbs, and the symptoms didn't point to fuel starvation. The bike would run excellent, until shut down. The difficulty starting got worse and worse until it wouldn't even start cold... I ordered a new CDI and coil off e-bay, and that problem seems to be resolved... only to lead to a new one. I think it was the coil, because the bike seems to run the same with either CDI. It starts, runs fine for the most part, but then out of nowhere will just lose power alltogether and shut down. It doesn't seem to be fuel starvation, because I can start it, hold the throttle so the revs are up and it will run fine, until I close and re-crack the throttle, and it sputters, and dies. It's fairly easy to re-start, usually needing only a few kicks, but continues to randomly sputter and die whether warmed up or not. I've set the pilot jet, spark isn't phenomenal but seems better than before, any other guesses what might be causing this? When I had the carbs off, I cleaned the jets thoroughly, the emulsion tubes, all passages etc with carb cleaner and compressed air. I'm stumped.. anyone ever have a similar problem?