Help Low Compression 95 Evinrude Ocean Pro 150

I'm hoping someone can help me understand why my compression of my 1995 Evinrude Ocean Pro v6 150 is 90psi in each cylinder.
I have owned the motor for 5 years for recreation use. I have never had a
problem and it is a strong powered always reliable motor. It always starts and runs incredible. I started it for the first time yesterday in 3 years and it fired up immediately even with the old gas.
I now have the motor for sale, and the compression was tested by a
potential buyer and he reported 90 psi in each cylinder, he said this is no good.
This shocked me becuase I have maybe put 50 hrs on this motor in the last 5 years. And before I bought it it was used by the harbor patrol for less than 1 season. So it should be almost a brand new motor. Any thoughts on this would be appreciated. Thank you

Re: Help Low Compression 95 Evinrude Ocean Pro 150

90psi in each cylinder is rather low. You really want to see over 100 on each and within 10% of each other. However, since it's low across the board, my guess is your motor needs nothing more than a good de-carbon.

Decarbon method

Re: Help Low Compression 95 Evinrude Ocean Pro 150

The engine is fine. Compression gauges will read a little differenly. The piston design in this engine will have lower compression at cranking speeds. If the prospective buyer is unsure, have a cylnder leak down test done on it.

The biggest factor on compression is that the cylinders have a less than 10 psi variance as was posted earlier. The reason behind this therory is the chances of having the compression low in all cyliders the same amount is virtually none. I woulod be confident in this engine at 90 acrossed the board

Re: Help Low Compression 95 Evinrude Ocean Pro 150

i use this method of decarb. i agree the guages are different, and those bigger motors show less compression, than the smaller ones. try another guage. all plugs out, turn over till the reading quits going up.
Decarb, take a can of seafoam put 3/4 of it in the gas tank, with only 1 gallon of premixed gas. put the rest in a spray bottle. start the engine, and let it come up to temperature. then remove plugs, and them some real good shot of seafoam into the cylinders, replace plugs, let sit 15 minutes. restart, and spray the rest of the seafoam into the carbs, so the the motor almost stalls, wait and repeat until the seafoam is gone.then take for a wide open spin. then put in new plugs, ad premixed gas to the tank, if you don't not have vro, and take it for a wide open throttle spin. it is going to smoke like a house on fire, during this process.

afterwards compression.recheck

Re: Help Low Compression 95 Evinrude Ocean Pro 150

Thanks for your replies!
The potential buyer said the motor should have a compression of 120+.
However reading through these forums I have seen that evinrudes had lower compression in the mid 90's. Is this true? Does anyone know what the factory
specs for compression on this motor is? Model # E 150 EXEOM.
Thanks again for your help!

Re: Help Low Compression 95 Evinrude Ocean Pro 150

J/E did not print compression specs for their engines, they printed that they want the hightes and lowest cylinder to be with in 15 psi of each other. The reason for this is as earlier post say, gauges are different and they did not want owners and techs to get hung up on a specific number.

Re: Help Low Compression 95 Evinrude Ocean Pro 150

Thanks to everyone for replying!
I will try the decarbon method and see if the results increase.
I just hate to try to fix something if it isn't broken,
It's been a great motor always no problems, but if these numbers mean
that much to buyers I will try to get them up.
Thanks again for your help!

Re: Help Low Compression 95 Evinrude Ocean Pro 150

different type motor test differently. cross flows, loopers.

Re: Help Low Compression 95 Evinrude Ocean Pro 150

This Ocean Pro 150 is loop Charged, so it must be a looper.

Re: Help Low Compression 95 Evinrude Ocean Pro 150

90 lbs is fine. Actual static compression numbers have a lot to do with port timimg. If a given design has low exhaust port timing then the static compression numbers will be higher than a similar design with higher exhaust ports. However the motor with the higher exhaust ports will probably be faster.

You probably didn't want to sell the motor to that guy anyway. Someone with that little knowledge is probably going to ba a real pain anyway. If he is basing his purchase strictly on looking for 120 lbs he'll need to look for a crossflow. Then let him put it on a boat like yours and you can see who's faster and burns less fuel. You'll win that bet every time.

Those motors are pretty hard to find. Don't give it away, that's a great design.

Re: Help Low Compression 95 Evinrude Ocean Pro 150

Thanks again to everyone for your replies!
I have learned more today about my motor than I have in the past 5 years.
All I ever knew was I didn't have to question it's performance..and it never let me down. So when this guy said I had a dud, I almost fell over...
However, thanks to your knowledge, I now feel confident as I ever did, with the added inteligence and knowledge that my Looper motor has higher exhaust ports and lower compression at start speed. And that the important thing here is the compression is 90 across the board with no variation over 15%. So basically thanks for giving me my confidence back that this is a great motor.
Thanks again!