Hey all, I recently picked up a 1982 CB900C in non running condition. 44K New battery, spray clean of the carbs and it started right up but was smoking and backfiring. Compression was low in the middle cylinders so I did a valve adjustment. After buttoning it back up, it started, less smoke, still smoking though (likely valve seals) and it had a bad vacuum leak somewhere and was till backfiring when it warmed up. I sealed things up and when I started it, it seemed happy until it started to warm up. It sputtered some but smoothed out as I decreased the choke. After idling 30-40 second with choke off, the idle dropped out and eventually it died and would not start again. I pulled the plugs and they are black, and in the right two cylinders, the plugs were actually wet and, oddly, the pipes on those cylinders were actually cool. Thinking coil fade, I checked the spark and they were all pretty good. Visible under fluorescent lights. I wire brushed the plugs, set the a/f screws to 2 turns out, let the engine cool some and tried to start again and it didn't start. Compression #s: 160,180,120,150 The cold cylinders are the lower compression, but they should still be ok I reckon. The jets are stock size and the air filter is a Uni. That filter may be gummed up with oily backfire though. Thinking its 'flooded' I pulled the plugs and will let it rest for a while. I examined the Air Cutoff valve on carb#1 and it appeared to be in fine shape. I have not torn into the rack to examine them all. I have been running a strong mix of SeaFoam during my tests, this last even was run with fairly fresh, 87 octane with no SeaFoam Other than cleaning that airfilter, is there something obvious, or not obvious that I haven't checked yet? Thanks for any thought or input!