Burned Piston

[dcracn24]

I just pulled the head and found the exhaust side of my omc 112 cross flow piston was warn or burnt and the rings look snapped and I have no commpression. <br /><br />Somebody told me I shouldnt be trolling with such a big motor and that problem. Is that a true statment?? All the other cylinders look fine.

 

[Solittle]

Re: Burned Piston

They didn't design em to burn pistons. They can carbon up to the point that a ring might stick and break. That is why it is a good idea to clear them out once in a while by putting in neutral and hitting the throttle. Also it is a good idea to decarbon those motors once or twice a year. <br /><br />Was the other cylinder carboned up real bad?

 

[BillP]

Re: Burned Piston

No matter what speed you run this can happen. A cold running engine will make it happen faster. The culprit is most likey crud build up from lack of decarbonizing. Build up on piston crowns will hold heat and eventually burn a hole right through them...then loss of compression. Rings stick, scuff and then break.

 

[dcracn24]

Re: Burned Piston

the other cylinders look great and it never seemed to run like it was loaded up or anything. The one bad piston was warn from the rings to the top on the exhaust side and you can see the rings are broken. there is nothing wrong with the top center of the piston. I wish we could post pictures because I have some real good ones!!<br /><br />Whats decabonizing?? how do I decarb them??<br /><br />THANKS

 

[BillP]

Re: Burned Piston

Sounds to me like it was run without oil...but from here that is easy to say and doen't mean anything but opinion. Decarbing is a process of chemically removing carbon & deposit buildup inside the combustion chamber. You spray or inject through the carbs and let sit for awhile. Then start up and clear the cyls. The motor has to be warm for best results. Done properly once a year it keeps the insides like the day they came off the production line...at least OMC Tuner brand does.