View Full Version : Compression 30 hp KOhler spec
05-05-2007, 03:29 PM
What should the compression be on a 30 hp kohler when it is new, I checked mine to see how it was.
05-05-2007, 05:33 PM
You really can't get an accurate reading because the ACR holds the exhaust valve open too long at cranking speed. I'd venture to guess a slight difference in crank speed would have an effect.
05-05-2007, 09:15 PM
As Bill stated there is no accurate or set compression reading due to variances with ACR's.
If a leak-down tester is not available a compression test will give some info. of the condition of a engine.
Engines with/without ACR should have at-least 60 lbs compression to start and at that low reading could be harder to start.
A compression test on a twin cylinder engine w/wo ACR can give a good idea of any major problems by the variance between the cylinders (cylinder balance). For example; If one cylinder tested at 180 lbs. and the other tested at 110 lbs. one could be safe in thinking there is a problem with the low cylinder.
That's where the leak-down test comes in, To determine what the problem may be, Valves, rings or blown head gasket.
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