Compression testing for saws

[Ax-man]

Can any one give me some numbers for doing compression tests on saws with a compression gauge for different size saws ??

The only reference I can get on this is for those old Homelite 925 's . I think they were in the 5 cube class, the book I have calls for 125 lbs for this size saw for this make.

Any bits of info on this would be helpful, putting your thumb over the spark plug hole doesn't always tell me what I want to know.

 

[jbrody44]

My Husq 55R would just start with about 70 lbs (after 3 pulls) and scored jug and piston. After I rebuilt it, I was around 125-130 lbs if I remember correctly. I don't know what the comp is supposed to be for factory spec, but it sure runs well now. I used a regular automotive comp tester and couldn't thread it all the way into the port (clearance to the piston), so maybe my reading wasn't even completely accurate.

 

[tony marks]

thisaint the technical info u looking for.
but just lay it into an appropriate sized hunk o hardwood.[for the saw]
sharp chain and she dont bogg .. u got enough compression. like i said... not what u ask,,but i dont even put my tester on the saw anymore...the mechanics here can tell u what u ask ,if they choose to.

 

[NeTree]

Shoot for anything over a hundred.

 

[rahtreelimbs]

Funny that this thread came up. I just did a compression test on a Stihl 028AV that I have. On a cold test, ( no warmup, which after the fact I heard is a better way to test ) throttle held wide open, I achieved over 150 lbs. on the 3rd pull.