low compression

gig

Recruit
Joined
Jun 9, 2001
Messages
1
I have a 1967 6hp Johnson outboard the compression was low so i replaced the rings but it didn,t increase the compression very much before it was 40psi after it was 75psi any ideas
 

12Footer

Fleet Admiral
Joined
Mar 25, 2001
Messages
8,217
Re: low compression

It's normal for the compression to be lower than normal right after a ring job.<br />The new rings must "seat", or form to the walls of the cylinder walls.<br />You will get some blow-by until they do,usually after about 4 hours break-in.<br />Use 32:1 mix for the first tank,and carry an extra set of plugs (because they might foul on the oily fuel).<br />You may also have a reed stuck open on a glob of carbon. Try running some decarb thru it if your compression doesn't pick-up to specs after break-in.
 
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