To make a long story short(er), after a long ride in the rain, my '83 Nighthawk 550 was cutting out above 6000rpm or so. It would occasionally stutter all the way up. Sometimes it would rev cleanly, and sometimes it wouldn't.
I dug into it - cleaned out the air filter box (the air filter was a bit dirty), checked plugs, wires, spark, pulled off and cleaned out the carbs, cleaned the petcock, cleaned out the fuel line/filter, cleaned and packed all connections with dielectric grease (the connector from the wiring harness to the coils was loose), and checked for compression.
Everything seemed to check out (besides that connector). After putting everything back together, the bike wouldn't start at all. It backfires through the exhaust and the intake, occasionally throws fire out the exhaust, and sounds pretty bad. I hooked up my timing light and it's indicating that during cranking (and for the second or two that the bike seems to run after letting off the starter button) it's firing somewhere between the F and T marks.
The cam chain has been loose and rattling around since I got the bike 5000 miles ago. Fixing the automatic tensioner (requires pulling valve cover, oil lines, etc.) was on my to-do list for this next month already (along with replacing that weeping valve cover), but it seems like I might have been too late.
I have fuel, I have spark, I have air (I tried with and without the air filter, no change), and I have compression. I'm not sure what else it could be, unless there's something simple I'm missing. My best guess is that somewhere in trying to start it after fixing the cutting-out problem, the cam chain managed to jump a tooth or two. Is there any way to check this before I start pulling the engine apart?
