Briggs and Stratton compression?

chris in va

Chief Petty Officer
Joined
May 4, 2003
Messages
410
Finally got around to doing a compression test on the B&S outboard. The best I could get was 60psi. Is that about right? Most 4-stroke engines I've tested get at least 100psi.
 

voodoo

Petty Officer 1st Class
Joined
Jun 23, 2004
Messages
258
Re: Briggs and Stratton compression?

briggs rarely publishes compression ratios.. they say if you turn it by hand to the compression stroke, a rebound indicates satisfactory compression to start the motor.<br />At least for the lawn stuff.
 

ZmOz

Captain
Joined
Aug 13, 2003
Messages
3,949
Re: Briggs and Stratton compression?

Sounds a little low to me. Try putting some oil in the cylinder and see if it goes up any. A leakdown test is much more useful on a small engine...
 

chris in va

Chief Petty Officer
Joined
May 4, 2003
Messages
410
Re: Briggs and Stratton compression?

Alright, contacted the local Briggs shop. They said it's about right, but didn't have a clue to the power issue. Looks like I'm stuck with a weaker motor.<br /><br />BTW ZMOZ...can you believe 140psi on the XJ with that many miles? ;)
 

ZmOz

Captain
Joined
Aug 13, 2003
Messages
3,949
Re: Briggs and Stratton compression?

Hey...what do you expect from the 4.0? ;) Mine's got 200k, and doesn't burn a drop of oil. The hard to believe part is that your 4.0 seems to have less power than the briggs. :D
 
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