Compression Test Kohler CH26

[blink115]

Does anyone know what the lbs should be on a compression test for a CH26? Bought a used Kohler with 1800 hrs on it and wanting to know if the valves and rings are still good.
Thanks

[msafi65]

Just checked manual and compression isn't listed. They want an air pressure leak down test preformed. I just tested a nearly new 23 horse briggs and it was 155 psi with throttle open. It would not build compression with throttle closed. I would think 1800 hours is about run out as most aircraft engines are 2000 hr TBO.

[jtb51b]

THe tough part of checking compression on a small engine is spinning it fast enough. You see, these engines have a decompression "bump" in the camshaft that allows these tiny starters to start the engine. This little "bump" is bypassed by speed when the engine is running over starting speeds. Honestly, the REAL method for checking compression is either RUNNING on one cylinder and checking the other OR turning the engine backwards. In these cases an engine in good repair should see 125lbs or more. Understand you need to only run on one cylinder for a VERY short time as to not build up excess fuel wash in that non firing side. IMHO if a kohler command runs without smoking you have no worries of cylinder wear. These engines have ceramic lined cylinders so they do not wear quickly. In commercial mowers (terrible environment) you see 2000 hours of service life prior (or more) prior to a re-ring.. I built one last year that had 2600 hours and went back together with STD sized components.

Jaso

[blink115]

Thank you guys for the feed back! I'm going to tear down anyway and replace can and rods for more horse power. I'll just go ahead a replace rings while I'm there. Thanks again for the feed back!

[jtb51b]

Thank you guys for the feed back! I'm going to tear down anyway and replace can and rods for more horse power. I'll just go ahead a replace rings while I'm there. Thanks again for the feed back!

I agree completely! Theres is absolutely no way I would pull one down to add performance parts and not begin with a fresh set of holes! If you hone the cylinders out yourself be ready for a battle, unless you have machine tools it can be a bear.. Good luck, great engine to start with. I really like the command series, they are very durable and smooth running..

Jason