Compression on smaller saws

[sawjo]

I have been sorting out an older poulan limbing saw (model 20, XX) that rescued from the landfill. The saw started after a number of pulls which I am attributing to new lines/filter and carb clean. The piston and bore where in real good condtion - no scoring or dis-coloration. After running for few minutes and adjusting mixture and idle, the saw idled perfectly and revved out to max without hesitation - good runner I suppose. Here is the strange part, after the saw had warmed up, I shut it down and attached a compression gauge (it has a rubber whip that threads into plug whole and a quick connect to the gauge) and gave it several tugs with the throttle open - 75 PSI! Is that a little low or typical for older homeowner (though decently made) saw? Does the fact that it started and ran full throttle indicate compression is OK, depsite what the gauge says? :Eye:

 

[Chris11]

Hello,

does the same meter indicate higher readings on other similar size "healthy" saws?
I would check that first before puting too much faith in the reading.

Best regards
Christian

 

[sawjo]

Good idea. Maybe I am guilty of trusting the semi junky gauge - will try on a brand new Echo 341 I have.

 

[Lawn Masters]

I have a 2000, similar to, if not the same as the 20 xx. it reads about 5 psi right now, but I've had at best, 100 psi from it.