One cylinder low on compression

[rivetshaver]

To Bevan
If you have never done a compression test , please get someone experienced in the task to demonstrate. The process can be potentially dangerous. I have seen a person get hurt when the prop got away while under pressure.
Greg

[Bevan]

Originally Posted by rivetshaver

To Bevan
If you have never done a compression test , please get someone experienced in the task to demonstrate. The process can be potentially dangerous. I have seen a person get hurt when the prop got away while under pressure.
Greg

Thanks. I read through the Skyranch procedure and thought that the prop could easily start swinging if the cyl was not precisely at TDC. My new-to-me mid time engine has a history of consistent high readings (77-78). But since purchase, my mechanic's notes say cylinders 3 and 4 were both 70. I'm not too concerned at this point just wondering how the test is done, and little bit as to why I got two 70's. The engine has been pickled for about 8 months (before the latest comp test) and has since been repickled.

Bevan