Honda-SOHC
SOHC.co.uk Forums => CB350/400 => Topic started by: watty51 on February 01, 2022, 08:25:38 PM
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Hi all,
Just fitted new piston rings, refreshed all the engine gaskets etc, and thought while I was waiting for a new battery to be delivered I thought I would do a cold compression test.
No spark plugs in.
Full open throttle.
All carbs and air cleaner attached.
No battery so used the kick stater.
Think the results seem promising. Cylinder 1 155psi. Cylinder 2 150psi Cylinder 3 155 psi Cylinder 4 160psi
The compression on a warm cylinder according to the manual is 170 psi
Does a cold test give accurate readings or will the true condition of the engine compression only be found when a warm test is Carried out.
Ta Mark
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You won't get an accurate compression reading until the new piston rings have bedded in. Your readings at the moment sound fine to me.
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Not a bad result for new rings and cold. Should increase when hot as things expand and start to seal up better.
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Look like good readings to me as well - if it starts easily from cold as well great. As has been said they will improve as the rings bed in.