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Cylinder compression PSI please? 25 HP Kaw

1191 Views 6 Replies 2 Participants Last post by  MXHalofan
Anyone know what a good cylinder compression PSI is for a 25 Kaw? I'm worried mine is low. Went half last year with no throttle cable, just had the throttle stuck in the high position. Engine seems a little sluggish this spring. :hammerhead:

I got 90 on one and 105 on the other. TIA
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Spray some oil in the cylinder and see if it goes up that will tell you if the rings are going bad some what. Also, check the rocker lash. Furthermore, take the compression hose off and valve core out and hook it up to the air compressor and blow air into the cylinders and see if any is coming out of the intake or exhaust with the rockers off or at zero lift on the cam. 5-10% difference is ok 15 is kinda getting high.
Compression went up to 120 in both cylinders after spraying oil in there. Boohoo

Wonder if I can get away with new piston rings and honing the cylinders? Mower runs ok, but I'd like to get it back in shape.
Probably could but how many hours does the engine have? Normally the blocks just can't handle the harmonics of the engine after a certain amount of hours it's just aluminum. You could always put a sleeve in. Also, don't forget the rings could just have a bunch of carbon on them try some sea foam or soaking the cylinders in some marvel mystery oil or something.
Did you test the pressure with the engine warm?????
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