Low Compression in one cylinder 86' Evinrude 140hp V4

[biggjohnjeremy]

Hello everyone! I bought a 1989 Starcraft Eagle with a 1986 Evinrude 140hp V4 (looper??)(( S/N E140TLCDC)) last week. It runs but has really rough idle, and will only run with choke lever engaged. Its a real looker and got what I thought was a great deal on it. I put new gas in it premixed 50:1 and cleaned the carbs out, but nothing changed. So I got the compression tester out and had reading of 105, 90, 115, 110. I did the decarbing methods found on here hoping it was just stuck rings and it didnt help.

Anyone have some time to help brainstorm this situation? I took it to a mechanic and we will see what he says is wrong with it. He said if its bad rings or pistons it would be about 2k to fix. Would this motor be worth sinking that kind of money into? I also have a 78 Merc1150 inline 6 with even 115 compression but isnt running well (stopped messing with it when I got this boat). Which one to yall think would be worth putting time and money into?

thanks, and sorry for long post.

 

[flyingscott]

I would put the money into the 140 evinrude. It's a newer motor and parts will be more available.

 

[racerone]

Note----There is no " choke lever " on that big Evinrude.-----Look into issues with CRANKCASE compression on that Evinrude too.

 

[biggjohnjeremy]

racerone Ok, I will look up how to do that. Would you say these are sound enough motor to restore and put money into?

Also this is the same controller i have. It has that lever on the top, It wont run without that.
I was also wondering about finding a tach that would plug into that controller since it was the plug for one

 

[mav6759]

I had the same exact motor and I had low compression in the lower cylinder on the left hand side found out it was a stuck ring i did the decarb and I heard a pop and my compression went from 0 to 70I check the head gasket on that side I found out that the head gasket was damaged. I changed out the head gasket and my compression went from 70 to 100. after allowing the motor to run and heat up, my compression on all cylinders are now 150 just a thought don't forget to shoot a little oil in that cylinder...

 

[biggjohnjeremy]

I really hope that is all it turns out to be. How noticeably bad was the gasket after you pulled it off?