What should compression be 1989 Yamaha 200 hp??

[bowhuntrrl]

I'm looking at a 1989 200 hp yamaha outboard. The compression is fairly even 110-120 on all cylinders. That seems a bit low to me. Does anyone know the spec for what it should be ??? TIA.<br /><br />bowhuntr

 

[JB]

Re: What should compression be 1989 Yamaha 200 hp??

Howdy, Bowhuntr.<br /><br />That is fine compression. <br /><br />Anything over 100 psi is okay, but the important number is the difference between high and low cylinder, should not be over 10%.<br /><br />Good luck.

 

[Capt Ken]

Re: What should compression be 1989 Yamaha 200 hp??

Sounds good to me also. Remember that cranking speed is in direct relation to compression. If the battery was not real hot, it can result in a lower compression reading. Once had an engine that the first cylinder checked fine and the cylinders got lower as I went. Battery was getting weaker and affecting the cranking speed.