Force 90hp: Compression Test Feedback?

[Bigprairie1]

Ok here area few good questions for the mechanical ones out there:
What affect (if any) on the compression readings will a cold engine test vs. a warm engine test yield?
What affect (if any) on the compression readings will not having the throttle fully opened have?
As you can probably tell....I did my compression test...it went pretty good however I didn't do either of these things for it.
The motor runs really nicely...no problems so far. The readings I got under cold/closed throttle conditions were:
top: 117-118 psi / middle: 126 psi / bottom: 127 psi
Basically the 'math' shows a total % difference there of within 10%...so all good on that front. The motor has about 250-300 hours on it (well maintained) so I would expect it to have some reduction in compression from new.
Still....let me know your thoughts on the results vs the conditions.
Many Thanks.

 

[WillyBWright]

Re: Force 90hp: Compression Test Feedback?

You might get different readings from cold to warm, but that wouldn't be any concern unless one in particular was significantly different between cold and warm. Say one is fine warm but low cold. That would be something I'd want to look into. I do the vast majority of my compression tests cold.