Compression test results.....what do you think?

[Power_Dr]

I have a 1988 Evinrude 150 (E150TXCC) that the overheating alarm came on this past weekend, then we had no power. I did a compression test today and this is what I got.

The left three cylinders were 62 psi same on all three. The right three were 30 psi on the top and 90 psi on the middle and bottom. I am thinking that the head gasket is shot. The power head was replaced about 5 years ago.

My questions are:
1) how long do head gaskets normally last?
2) I know that they say not to pay that much attention to the actual psi readings, just that they are all similar, what about from one side to another?
3) It looks like I have a problem with the right side, do I replace the head gasket on the left side as well, or just leave it?

Thanks,

 

[jonesg]

Re: Compression test results.....what do you think?

1. UNTIL YOU OVERHEAT THE ENGINE.
2. I'd order 2 gaskets.

Check for slight warp on the heads, dress on a sanding plate.
Buy a sheet of fine wet/dry and do it on a sheet of glass, figure eights.

Then the thermostats, change them. I would also install a temp guage if you don't have one. Its one thing or another eh.

 

[jay_merrill]

Re: Compression test results.....what do you think?

You have both very low readings on all but one cylinder, which is still lower than it should be, and large psi differentials.

I would expect more than head gasket problems.

 

[tashasdaddy]

Re: Compression test results.....what do you think?

did you do it this way? http://forums.iboats.com/showthread.php?t=313884

i would try again with another tester. right now you have a sick motor.

 

[Power_Dr]

Re: Compression test results.....what do you think?

I took out all the spark plugs, and pulled the lanyard, then cranked for about 2-3 seconds. I will replace the thermostat as well. Where do you install the sending unit for a temp guage?

Thanks for the replies.

 

[tashasdaddy]

Re: Compression test results.....what do you think?

i would install a water pressure guage rather than a temp guage.