Hi,
After revising and selling my first CB500 four, I recently bought a "new" 500 to work on (the condition of my 550 is just too good to keep me busy).
Anyway, I ran into some trouble: after starting up, exhaust headers 1, 2 and 3 are too hot to touch after 30 seconds. Header 4 however, doesn't get any warmer than a rare steak.
Compression on all cylinders is around 134 PSI (cold engine)
All spark plugs are new NGK D7EA's and #4 fires just like the others: significant blue spark.
Could it have something to do with the ignition timing or the carbs?
Hope I'm not double posting. Could not find a similar subject.