<VV> compression test

[djtcz at comcast.net]

> From: GYoungwolf at aol.com 
> Subject: Varying Compression Readings? 
> 
> I was checking compression on a '64 110 engine today, when I noticed that I 
> can "pump up" the readings. Am wondering what that means? I was using a 
> screw-in (sealed with an 0-ring) compression gauge. With a couple of revs, the 
> readings on all cylinders were a fairly consistent 95-100. But, if I continued 
> to 
> crank the engine, the compression reading on several of them could be pumped up 
> to 125+. What, if anything, could this mean? 

Until just last year I disregarded the "open throttle fully" part of the comp test instructions.  Then a BMW 2 cyl motorcycle dealt only scary low readings when tested with closed throttle.

I'd probably test the gage try again with warm engine and throttle open, and hope for something higher