1981 Evindrude

[galstron1]

I have an 81 Evinrude that has black carbon on top of the piston head. <br />What can I use to clean it off. And with the black carbon on the head will that <br />affect the speed and power of the motor.

 

[oldboat1]

Re: 1981 Evindrude

I assume you have the head off. With the head off, I've sprayed the tops of the pistons with carb cleaner, then carefully wiped them with a rag -- takes a few attempts for heavy carbon buildup. After finishing, I carefully cleaned everything with a soft rag and sprayed the piston head and the walls with WD-40.<br /><br />I don't know if this is a dangerous little exercise, though, so wait for some more responses -- also some info on the technical question about whether the carbon buildup (and to what degree) is a problem). <br /><br />Good luck.

 

[galstron1]

Re: 1981 Evindrude

When I replace the head gasket I noticed the carbon. But did not have the time to clean it.<br />Ii was about to rain, so I did not clean the carbon at the time. Will the carbon hurt the motor. and how long can it last with the carbon on the piston heads.

 

[oldboat1]

Re: 1981 Evindrude

I've learned in similar discussions here that it's carbon between the rings and the walls that makes for problems (at least that's what I think I heard). On the piston heads, it's not so serious -- probably just a matter of degree.<br /><br />Wait for more technical advice, but it doesn't sound like you have anything to be too concerned about -- probably normal buildup.

 

[rickdb1boat]

Re: 1981 Evindrude

1981 glastron, <br />If it is just a light build-up, kinda just discolored, then you would be fine to run it. If it is heavy, where you can actually see a layer on the piston, then I would get to it as soon as possible! They do have products to decarbonize the engine, but as long as you have no problem getting to it, I would just go ahead and clean it "Manually" as was suggested by Oldboat1! If it's real heavy, you can spray it and let it sit, and CAREFULLY scrape most of it away. Thats the way I cleaned up the carbon on a 28 Johnson I used to have. It was easy to pull the head and just clean it every year or two. Just my thoughts! Good Luck, Rick

 

[galstron1]

Re: 1981 Evindrude

The carbon is just on the piston head. Not on the walls. The walls are shinny and without scratches. I will wait for further replys.<br />Thanks for your suggestions.

 

[petryshyn]

Re: 1981 Evindrude

A small amount of carbon residue (1/32" or less)on the head and piston crown will not affect performance on your engine. The easiest way to remove this is to decarbon more often.....

 

[galstron1]

Re: 1981 Evindrude

What type of additive can I add to the gas to remove the carbon on the piston head.<br />Or do I just need to remove the head and clean it manualy<br /><br />81 Glastron

 

[wilde1j]

Re: 1981 Evindrude

1981, OMC has two products, Engine Tune, an aerosol decarbonizer. Just follow the instructions on the can. The other is Carbon Guard, which is added to the gas and prevents carbon acumulation. Use the Engine Tune every few years or about every 150 to 200 hours and Carbon Guard all the time.<br /><br />There are other products for decarbing, such as Sea Foam (available from NAPA dealers, and other products for preventing carbon accumulation in 2C motors.