Evinrude 60hp Overheat Please tell me if the piston are OK (not melted)

[lmcjmgo]

Hi all,

I have opened my engine because the cilinder compresion was 120- 40- 120. The second cilnder was down the second.

When I open it the head gasket is burned.

Please see attached pictures.

Somebody mentioned to me that the piston can be melted and that means open the engine and redo it.
Based on the pictures, can you tell me:

1) Are the piston melted? Do I have to replace them or I can test the compression that I have with the new gasket and continue running.

2) how I can test the overheat beep? because I do not remember that I had any alarm about it.

3) Base on what you can see, may I replace the thermostat. water pump, gasket and continue using it.

 

[RogersJetboat454]

Re: Evinrude 60hp Overheat Please tell me if the piston are OK (not melted)

Piston #2 between the 9 and 10 o'clock position looks a little crispy in your pic, and almost looks like you can see a bit of the ring. Can you get a closer picture of that area? How does the cylinder wall look for piston #2, and the others? Rotate the engine, and snap some photos if you see scratches, gouging, or spots with gray stuff stuck to them.

 

[fishfeatures]

Re: Evinrude 60hp Overheat Please tell me if the piston are OK (not melted)

Piston #2 between the 9 and 10 o'clock position looks a little crispy in your pic, and almost looks like you can see a bit of the ring. Can you get a closer picture of that area? How does the cylinder wall look for piston #2, and the others? Rotate the engine, and snap some photos if you see scratches, gouging, or spots with gray stuff stuck to them.

unfortunately #2 does look fried. Compression figures were always a bad sign.

 

[WernerF]

Re: Evinrude 60hp Overheat Please tell me if the piston are OK (not melted)

I wouldn't be that pessimistic.
The head gasket is blown at #2 (pics from your older post), and with a little luck thats the only reason for the lack of compression. So turn the flywheel and look at the cylinder walls. If not scratched, turn the flywheel to #2 TDC and clean the piston ground with sand paper in order to see if 10 o'clock position is really melted. If not too bad, I would invest a head gasket and give it a try.
If you can reach 100+ psi again, replace water pump, thermostat and relocate the tell-tale to the top of the block as shown in a service bulletin here on page 117: http://issuu.com/cdielectronics/docs/troubleshootingguide?mode=embed&layout=http%3A%2F%2Fskin.issuu.com%2Fv%2Fcolor%2Flayout.xml&backgroundColor=000000&showFlipBtn=true

 

[F_R]

Re: Evinrude 60hp Overheat Please tell me if the piston are OK (not melted)

You can clearly see the ring on that one piston. I would NOT run it until it is replaced. There is great danger of it breaking up completely, and then you will have a much bigger problem to deal with. You are lucky you caught it in time.

When you tear it down, don't be tempted to ignore the exhaust covers and gaskets. They are almost certain to be heat damaged and possibly warped.

 

[lmcjmgo]

Re: Evinrude 60hp Overheat Please tell me if the piston are OK (not melted)

HI all,

Thanks a lot Guys, Your help is really appreciated.

To give you a better idea of the situation, I did a video, you can see it and give me you opinion about it.

Some more extra info:

1) The Head cylinder cap (cover) is in good shape, not smelt at all , clean.
2) yes piston #2 is melted a little, as you can see you can see the ring; however, looks like it still have compression
3) I have passed my finger on the second cylinder and I can feel a small scratch at 10 o'clock position and Just at the border of the cylinder (the piston does not touch it) I can feel and small (0.1 millimeter) burr that looks like was generated by the piston melting at that position.
5) in case that I have good compression when I close it, what is the risk to keep it running (I called and the marine ask $3700 to redo the engine)

Thank a lot!!!!!!!!

 

[RogersJetboat454]

Re: Evinrude 60hp Overheat Please tell me if the piston are OK (not melted)

5) in case that I have good compression when I close it, what is the risk to keep it running (I called and the marine ask $3700 to redo the engine)

Pretty high. If that ring does not have enough real-estate on the piston to keep it from over flexing, its going to break. It's brittle cast iron, not meant to be floating around, but needs support from the ring lands on the piston. The developing scratch in the cylinder may be a sign that things aren't going well.

You may not need to do the whole engine over. If you're lucky that scratch is merely a flesh wound that you can lightly hone out and install a new standard sized piston and rings for that cylinder. After that you would need to determine why it melted down. If it was just a Simple localized overheat, or if the carb was full of trash, and leaned that cylinder out.

If you're a handy guy, and get your self a factory manual, you shouldn't have too much trouble tackling this one your self.

 

[F_R]

Re: Evinrude 60hp Overheat Please tell me if the piston are OK (not melted)

Agreeing with Roger, there is a high probability that piston or ring is going to break. When it does,it is all over but the crying.

 

[nwcove]

Re: Evinrude 60hp Overheat Please tell me if the piston are OK (not melted)

Agreeing with Roger, there is a high probability that piston or ring is going to break. When it does,it is all over but the crying.

^+1......its not a matter of "if"...its a matter of "when".

 

[lmcjmgo]

Re: Evinrude 60hp Overheat Please tell me if the piston are OK (not melted)

HI Guys,

Thanks a lot for your help.

Looks like I will have to open the engine and change piston and ring.

I am very handy, However, I do not have outboard motor experience therefore:

1) what is a good manual that explain how open it and change ring and Piston. I have a Seloc manual but it is very old. Do you have any recommendation for manual or video?

2) Do I have to change all pistons and rings or just all rings and the piston that is affected.

3) DO I have to change all power head bearing?

4) any video or instructions about from where I have to start to open it and the sequence that I have to follow is very appreciated.

5) I have tested the temperature switch is bolling water and it works well; however when I ground the cable the alarm does not sound. does the engine need to be running to test the alarm or just in contact?

Thanks a lot for your help.

 

[RogersJetboat454]

Re: Evinrude 60hp Overheat Please tell me if the piston are OK (not melted)

HI Guys,

Thanks a lot for your help.

Looks like I will have to open the engine and change piston and ring.

I am very handy, However, I do not have outboard motor experience therefore:

1) what is a good manual that explain how open it and change ring and Piston. I have a Seloc manual but it is very old. Do you have any recommendation for manual or video?

2) Do I have to change all pistons and rings or just all rings and the piston that is affected.

3) DO I have to change all power head bearing?

4) any video or instructions about from where I have to start to open it and the sequence that I have to follow is very appreciated.

5) I have tested the temperature switch is bolling water and it works well; however when I ground the cable the alarm does not sound. does the engine need to be running to test the alarm or just in contact?

Thanks a lot for your help.

1. Get your self a genuine OMC/Evinrude manual. Anything else, and you are asking for trouble with vague descriptions, and possibly the wrong information.

2. Inspect the pistons and rings, and decide accordingly. If you are lucky, you can hone just that cylinder, and install a new ring an piston. If you are un-lucky the cylinder is damaged, and needs to be overbored. Worst case is you find damage on other cylinders/pistons which would require the replacement of additional pistons.

3. Inspect them for your self. If they are in good nick, it's your choice if you want to replace them or not. If they are in poor shape, chances are the crank may look pretty sad too.

4. Maybe?? Look around on Youtube for videos to get a general idea. DO NOT use the info on Youtube as your engines shop manual though! Things may be different, or the person doing the video may have bad info.

5. I'll let the JohnnyRude Guru's answer that one.

 

[fishfeatures]

Re: Evinrude 60hp Overheat Please tell me if the piston are OK (not melted)

5) I have tested the temperature switch is bolling water and it works well; however when I ground the cable the alarm does not sound. does the engine need to be running to test the alarm or just in contact?

.

Just turn the key to the on position and ground the wire at the head and it should sound.