carbon build up on pistons

[gcman49]

I had my spark plugs out working on another problem and while they were out I checked each piston and it seems like there is a lot of carbon build up on all of them. I have a 78 evinrude140 and I know that evinrude makes an additive for the gas that is supposed to help clean them up. do these additives work? My plugs look pretty clean when I take them out and I try to make sure that I am running the correct fuel and oil mix. I would like to try to clean up the pistons short of tearing the engine apart. Any advice from anyone?

 

[Dhadley]

Re: carbon build up on pistons

Use a product called Engine Tuner. Follow the instructions on the can but DO NOT let it sit in the motor longer than 4 hours. I usually use 1/2 can and let it sit for an hour before restarting. The run it long enough to get it all out. You may need to change plugs after.<br /><br />A major cause of excess build up is lugging or "over propping" (bad term). If your motor is only capable of, say 5400, it will coke up quicker than if it was capable of 5800. <br /><br />Decarbon first and then we can deal with the set up.<br /><br />Good luck!

 

[kart33]

Re: carbon build up on pistons

Valvtec makes some wonderful decarbonizing products for the one time use and fuel additive. After using the decarbonizing spray in the carb the engine ran quite a bit better. Now I use the fuel additive. You can't arue with success.

 

[wippb]

Re: carbon build up on pistons

I have been looking for this product and cannot find it. Another product i have seen used on this board is Seafoam, can't find it either. Are there any other brand names that might work.

 

[Dhadley]

Re: carbon build up on pistons

Engine Tuner can be purchased from any Evinrude / Johnson (Bombardier Recreational) dealer.<br /><br />Good luck!

 

[mbb]

Re: carbon build up on pistons

NAPA carries seafoam, the aerosol version is called Deep Creep, I have seen it at O'reilly Auto Parts. It is handy to have the aerosol if you intend to spray it into carbs. Or you can use a trigger sprayer.

 

[gcman49]

Re: carbon build up on pistons

Thanx for all the tips. I found engine tuner at an evinrude dealer.<br /><br />Gcman49