1986 Mercury 115 hp decarbonize

[cheers731]

Hi folks,

Just bought a boat with a 1986 Mercury 115 hp 6 cylinder outboard. I used to deal with I/O setup and this is my 1st outboard and need help to build a quick learning curve. The engine is running strong but with lots of blue smoke. I plan to do decarbonize using Seafoam but not sure where to spray in or should I add it to the fuel. I will replace spark plugs afterward.

Any tips or advice are appreciated greatly.

 

[bilge rat jim]

Stay away from SeaFoam- it only contains alcohol, naptha and mineral oil. If you want a good de-carboning agent, try Yamahas' Ring Free plus, or a Chevron product called Techron. Both contain Benzene and zylene, good carbon desolvers. I'm sure there are other good carbon removers on the market, but I have had good success with both Ring free and Techron. Sorry, but SeaFoam is snake oil.

 

[Chris1956]

Cheers, Blue smoke from a 2 cycle motor is good.....Not many would critize Seafoam like Jim. Most think it is a good product. There is a sticky somewhere explaining how to decarbonize. I would recommend you run it for a while to get some experience with it before you decarbonize.

Normally you would change the gear oil and waterpump. They are the same ( or real similar) as on an Mercruiser. Also, do not forget to mix your fuel at 50::1.....

 

[bilge rat jim]

Cheers, Blue smoke from a 2 cycle motor is good.....Not many would critize Seafoam like Jim. Most think it is a good product. There is a sticky somewhere explaining how to decarbonize. I would recommend you run it for a while to get some experience with it before you decarbonize.

Normally you would change the gear oil and waterpump. They are the same ( or real similar) as on an Mercruiser. Also, do not forget to mix your fuel at 50::1.....

No need to premix the fuel- 1986 models have Autoblend, 1st gen oil injection.

 

[cheers731]

Thanks for the tips and advice, really appreciate it.

 

[wired247]

FWIW I use the penzoil premium synthetic blend 2 cycle oil. Relatively cheap at $16 a gallon on sale and it doesnt smoke at all.