Compression ratio - 90 HP Outboard

lelliott19

Recruit
Joined
Jul 23, 2009
Messages
2
What is the desirable compression ratio for a 1993-94 90HP Yamaha outboard? Ours checked out the same in all three cylinders 130 psi. Since all three cylinders checked outthe same, I am assuming that is a good sign, but I don't really know what it is supposed to be.
 

deejaycee_2000

Captain
Joined
Mar 28, 2006
Messages
3,447
Re: Compression ratio - 90 HP Outboard

Yes that is a very good sign, compression is perfect .....
 
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