Compression Gauge Recommendations

Arborist Forum

Help Support Arborist Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

jwarf

ArboristSite Lurker
AS Supporting Member
Joined
Dec 7, 2022
Messages
5
Reaction score
0
Location
couch
Looking to see what folks are using to test compression on their chainsaws. It seems like for small engines you may just want a unit that has a Schreader valve at the end of the hose. Currently looking at a matco and a mityvac. Thanks for the feedback!
 
Looking to see what folks are using to test compression on their chainsaws. It seems like for small engines you may just want a unit that has a Schreader valve at the end of the hose. Currently looking at a matco and a mityvac. Thanks for the feedback!
Just remember that a compression reading is really secondary to examining the piston through the muffler/exhaust port. I have lots of stories both personal and on this forum where an engine with measured good compression had a scored piston / cylinder.
 
Agree - save money for VAC/PRESS tester, but some may want a compression reading if you're selling the saw. The Schrader valve must be as close to the combustion chamber as possible, especially on small cc engines. Be cautious if using an adaptor, it can increase combustion chamber volume and reduce the compression reading. I just experienced this on an MS171 which uses a much smaller spark plug - the adaptor changed the compression from 130 to 90 psi. I modified the adaptor to keep the valve at the end.

btw, Amazon has a gauge made by Lisle that works well for about $27.
 

Latest posts

Back
Top