Topic: Bad compression on #2

[cb650guy]

Hello all,
I am working on a 1980 CB650 custom.  The compression on cylinder #2 is low, around 80 psi with a cold engine.  I have been told that if I can get the bike running (it hasn't run in years) that the engine might heal itself by burning carbon deposits and removing rest, and the compression may go up.

Does this sound possible?  What are my chances?  I have no experience with rebuilding an engine and I am not keen on trying.

Thanks

[OldSchool_IsCool]

Its not so much what the compression reading of one cylinder is, but rather, how different are the readings between all 4 cylinders.  Also, be sure to run the tests with the choke open and the throttle held at WOT.  Ideally, the engine should be warmed up too.

See if you can get the engine running and go from there.

[MoMo]

I have resurrected several old Hondas that had been sitting for years by adding an ounce or so of Seafoam to each cylinder, compression rose from 60ish cold to enough to get the bike started. Still running fine to this day.  Try it for a couple days and see if compression rises. As stated make sure choke is open and throttle is wide open.  Best of luck, Larry

[cb650guy]

Thanks Larry.  I will give that a try.