[samahi72]

I have been told that you can not use a compression tester on a lawnmower engine to diagnose the rings and valves. Curious as to why not? If I have been mislead, what kind of readings should I get and what is the technique to using it, i.e. how many compression strokes, etc.

 

[Brad]

Greetings. I don't see why you could not use the compression tester to check your engine. The only thing would be if the engine had a compression release, which most walkbehinds don't. I would expect anywhere from 100 to 130 lbs would be expected.

 

[junebug1701]

Greetings. I don't see why you could not use the compression tester to check your engine. The only thing would be if the engine had a compression release, which most walkbehinds don't. I would expect anywhere from 100 to 130 lbs would be expected.

I believe that most walk behinds DO have the compression release. Briggs marketed it as their "Easy-Spin" system and labeled the engines as such starting in the '60's. The trick to testing the compression is to pull it hard enough and fast enough to override the compression release. It only works at very slow rpm's.