Compression

[Clyde S. Dale]

Anyone ask if you are at elevation? The higher the elevation above sea level, the lower the compression readings will be.

 

[grizz55chev]

Looking at old threads, there is some merit to your question. For every 1000ft adjust for aprox. 3 percent lower compression.

 

[Chris-PA]

I just got a new Husqvarna 550xp and tested the compression and it only came out to 90psi. So I tested the compression on my well broken in 562xp and it reads 105psi. I also have a Chinese Redmax clone that I got for fun and it reads even higher at 115psi. I always thought that 150psi was considered the "A" grade so why are mine so low? And is it normal for these pro grade Husky's to have lower compression?

Which RedMax clone is it?

 

[bikemike]

Which RedMax clone is it?

How did I know that was coming lol

 

[Chris-PA]

How did I know that was coming lol

There is a method to the madness! I've been thinking about compression ration, combustion chamber volumes, squish band clearances and the pressure people measure on gauges. My G621 clone has a quite small combustion chamber, so if it's one of those then that would be an interesting data point.