I'll try to keep this brief (unlikely). I've completely customize a 1980 KZ650 F1 into what you see as my avatar image. I've gone through everything, short of a total engine rebuild. I drove it all year last year and the first half of this year with little issue. However, one persistent issue I had was the exhaust header on cylinder #2 being at the same temp as the other 3. It didn't really bother me but now I'm obsessed with it and NEED to figure out why. This is mostly the case now as I'm trying to re-tune the carbs and the plug on #2 is wet, black, and oily. In fact today there was oily gas dripping from the exhaust drain hole. The other 3 are completely clean and/or slightly white.
Current setup:
-K&N pod filters (I know, I know...)
-Rejetted (115 mains, 15 idle?)
-Aftermarket muffler welded to original 4-into-2 headers. Lightly baffled mufflers (cheap shorty ebay ones)
What I've done:
-New ignition coils
-New NGK plugs
-New timing condensers
-Timing calibrated carefully
-Carbs balanced to around 200mmHg
-Floats dry calibrated (not wet, don't have the little connector thing)
-Biggest thing: ALL 4 cylinders test right about 150psi consistently!
Last piece of info: after a ride home from work, headers on 1-3-4 are around 250-350 deg F. The header on #2 is around 150 F. So not totally cold. It seems to fire occasionally but not consistently? It also seems to fire only when getting beyond idle circuits and getting into the main jet throttle level. So my final thoughts here are to rejet the pilot jets with something bigger. 1-3-4 plugs are very white/clean at idle despite air screw basically being all the way in.
Thanks to those who read through all of this and have any thoughts for me!! I really hope this is a carburetor issue and not an engine issue!