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Compression test numbers on a two stroke 2 cylinder outboard

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March 31, 2019, 08:44 PM
old rugged cross
Compression test numbers on a two stroke 2 cylinder outboard
85 and 92.

I know you want them close. I like them a bit closer.

Am I safe at these compression numbers?



"Practice like you want to play in the game"
March 31, 2019, 08:56 PM
220-9er
The variation isn’t that much and there is a lot of other info needed. Hot or cold, hand crank motor or electric start, what’s the book say.
If anything, they look on the low side to me.


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March 31, 2019, 08:57 PM
shiftyvtec
Yeah, I'd say their pretty low. If memory serves, they should be within 10% of each other.
March 31, 2019, 09:20 PM
sigmonkey
7 is within 10%.

You are fine.

Most 2 older stroke outboards are bout 6:1, so 80-100 is the "normal" for most outboards.

If it is running well, and putting out adequate power, motor on.




"the meaning of life, is to give life meaning" ✡ Ani Yehudi אני יהודי Le'olam lo shuv לעולם לא עוד
March 31, 2019, 09:30 PM
shiftyvtec
Oops, guess I should have specified that the numbers are within the recommended 10%. I have only dealt with 700cc 2cyl jetski motors primarily and they are typically sporting about 120psi cold when stock and in good condition.
March 31, 2019, 10:05 PM
sigmonkey
Yep. "Watercycles", and a wee bit hotter. Big Grin




"the meaning of life, is to give life meaning" ✡ Ani Yehudi אני יהודי Le'olam lo shuv לעולם לא עוד
April 01, 2019, 12:18 AM
old rugged cross
Thanks guys



"Practice like you want to play in the game"