2000 250 ox66 compression

[FinIdiot]

New to forum. Been lurking for several weeks now since I am looking for 30 marlin. Found one that I'm interested in and had compression check done after sea trial. All cylinders were between 100 and 105 on both motors. Seems low from what I have been reading. Would numbers be lower on a warm engine compared to a cold engine. Any help would be appreciated.
Thanks

Jeff

 

[catch22]

I had a 2000 Yamaha 250 and the compression was between 115 and 120 on all cylinders.

I don't know about cold vs warm results, but I think readings should be taken with a warm engine.

I think the most important thing is, that all cylinders have a reading within 10 percent of each other, and yours are, so that's good.

Also... a "leak down" test is better.

 

[3rd Day]

Catch 22 is correct. Operating temp/warm is an accurate indicator of compression readings. On a boat that size/value, I'm guessing some service records might be available, including psi readings from what is considered a "tune up" on an outboard engine. Good Luck.