I have just recently purchased a 99 intruder 800. At idle both cylinders seem to run equally. While riding only the front cylinder seems to be firing and under hard Accel it feels like the rear cylinder kicks in for a second or two. While cruising the rear cylinder exhaust pipe is cool enough to grab and the front is super hot. I have pulled both carbs apart and cleaned several times. I know they are clean and have found no problems with either of the internals. I have put in new plugs and a new coil on the rear cylinder. No change. I do know it is running extremely rich on the rear. I have no idea what to do next. I haven't been able to sync them properly yet. Could they be so far out of sync it would cause this issue? Please help as I'm ready to sell the bike. Compression is also good on both cylinders.