Low compression head gaskets

boltbreaker

Petty Officer 3rd Class
Joined
Aug 31, 2004
Messages
76
What kind of compression increaseas can one expect by installing a low compression head gasket? How bout if we shave .030 off the head to go with it?<br />Johnson v-4 with 85 pounds on all four.<br /> -BB-
 

G DANE

Commander
Joined
Nov 24, 2001
Messages
2,476
Re: Low compression head gaskets

The low compression gaskets are to lower high compression, getting low-octane gas to burn better. If you have low compression, but even on all cylinders, try to check with another gauge, all 4 cylinders rarely wear out equally over time. If they are, how does it run, it might be time for an overhaul, but seing motors that actually wear our is rare, they last a long time and something else normally happens before.
 

moderator1

Lieutenant Commander
Joined
Dec 5, 2002
Messages
1,668
Re: Low compression head gaskets

Ditto on the double-check with another gauge...<br />If all 4 are the same, I don't think you have an issue. I have, however, seen this condition when a person disconnects the fuel line and runs all of the fuel out of the engine untill it dies, which is a very lean condition causing "dry" cylinders, and as a result, the compression may be somewhat low on all...85lbs????...I don't think it would be that low.
 

BoatBuoy

Rear Admiral
Joined
May 29, 2004
Messages
4,856
Re: Low compression head gaskets

Also make sure you're using a "hot" battery. A partially discharged battery will crank slower, resulting in lower compression readings.
 
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