89 Evinrude 150hp compression question.

[Valv]

I just bought a 1989 Evinrude 150hp, I checked compression and I had 95lbs on each cylinder, tested 3 times each. This motor has been sitting for few months (but amazingly started right away).<br /><br />Is this reading (cold, closed throttle) low and I should be concerned, or could it be ok after a good decarb ?<br /><br />Thanks

 

[OBJ]

Re: 89 Evinrude 150hp compression question.

Hi Valv...<br />Tell ya' what to do. Start her up and get her warm and shoot some engine tuner into her. Let her set for a while, following directions on the tuner, and start back up. Let her run and blow all the carbon out. Then take another compression test. 95 ain't bad. I like'm around a 100 or better. Don't sound like you got much wrong that a decarb won't make better.

 

[thosch]

Re: 89 Evinrude 150hp compression question.

I think you're OK, with the compression test conditions you stated. Readings are pretty even, at least. Decarb is always a good idea, especially when the history of the engine is not known. <br /><br />Hey, we still got some time before the ice is off the lakes up here, unless there's a secret in Lonsdale that the rest of us don't know about.

 

[Valv]

Re: 89 Evinrude 150hp compression question.

Thanks guys, I'll try tomorrow, if I can stand the cold outside.<br /><br />T.H. here in Lonsdale, we have a secret, it's called:<br />Mississippi at RedWing.<br /><br />You guys further up north there have: Mississippi at Ford Dam<br /><br />

 

[thosch]

Re: 89 Evinrude 150hp compression question.

Your right about the river. When I was a kid, we lived down near LaCrosse, and used to take boats out on the river (weather permitting) for most of the year. Fished by the Dresbach dam alot throughtout the winter. Spend most of my time now on lakes and the upper St Croix River (north of St Croix Falls/Taylor Falls).<br /><br />Good luck with the Evinrude.

 

[Joe Reeves]

Re: 89 Evinrude 150hp compression question.

Valv..... The compression reading of 95 psi is fine. Years back, the compression ratio was up to about 125/135 psi but due to the falling quality of gasoline OMC lowered the compression to compensate. Bottom line.... not to be concerned, that compression reading is okay.