Evinrude v4 140 compression help

[Glastrontizz]

Hi, I have a 1984 Evinrude v4 140. Model number is e140tlcrd. I was out fishing last week and it kept getting harder to start as the day went on. As we were heading into the harbor it sounded real muffled and was running like crap. I bought a compression tester and checked it today. I had 100 and 105 on the right side and 25 and 85 on the left side. I pulled the cover and found water and sand in on the back side of the cover. Then I pulled the head off and found some water around the cylinders. The cylinders don't look scored from what I can see. What should I do now. I don't want to spend a fortune on this since I bought the boat for only $1800 last summer. Here are some pictures.

 

[JB]

Re: Evinrude v4 140 compression help

When compression crashes on adjacent cylinders the problem is usually a blown head gasket between them.

What did the head gasket look like? That has a good chance of being the only problem.

 

[Glastrontizz]

Re: Evinrude v4 140 compression help

When compression crashes on adjacent cylinders the problem is usually a blown head gasket between them.

What did the head gasket look like? That has a good chance of being the only problem.

There is some water and corrosion behind the gasket on the lower cylinder. Should there be any moisture after the gasket? The first thing I plan on doing is replacing the head gasket and crossing my fingers. Should I spray anything into the cylinders? Thanks

 

[Glastrontizz]

Re: Evinrude v4 140 compression help

My measurements were taken cold with only one spark plug out each test. Not sure if this makes much of a difference. This was my first compression tests.

 

[Glastrontizz]

Re: Evinrude v4 140 compression help

In this picture is the circled area a sign of a blown head gasket?

 

[Glastrontizz]

Re: Evinrude v4 140 compression help

any help?

 

[G DANE]

Re: Evinrude v4 140 compression help

First - looking at the gasket mating surface, there could be signs of a blown gasket. Second - a good disassembling and carb cleaning would be in order, as both pistons looks light in colour and dry, indicating lean mixture that sure would kill the pistons and score the borings fast. Try with a new head gasket, oil the cylinders and clean the carbs. Do a search here on carb cleaning and do it properly, lots of people dont. Motor looks nice and clean. Run it a little, and post results. There should be water around the cylinders and under the head cover, thats the meaning of the cooling system.

 

[Glastrontizz]

Re: Evinrude v4 140 compression help

Should I use fogging oil?

 

[ezeke]

Re: Evinrude v4 140 compression help

Engine oil (TC-W3) is fine.

Whatever that is circled in the thumbnail does not belong there.

 

[G DANE]

Re: Evinrude v4 140 compression help

EZEKE is right, missed that.The carb cleaning is important, do a search and do it properly, or those cylinders will burn up.

 

[clanton]

Re: Evinrude v4 140 compression help

The water deflectors need to be changed 2 on each side. I would pull the bypass covers off run the piston down, look at the rings.