Compression Gauge Recommendations

[jwarf]

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!

 

[ammoaddict]

I have the mityvac. Comes with several hoses and adapters and spare valves.

 

[SteveSr]

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.

 

[Chevboy0167]

Pricey but works damn well.

https://www.ebay.com/itm/184739014961

This 1 a bit easier on the wallet.

https://www.ebay.com/itm/4013809667...daX8fxC8+V5libNWTpBxFt8w==|tkp:Bk9SR_bC7e-NYg

 

[stihltech]

Hold it by the starter handle, pull it over, remove the muffler. Save your money for the vacuum and pressure test kit.

 

[buzz sawyer]

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.