Yamaha C115 decarb

[wvstriper]

I recently decarb 'd my inherited Yamaha C115 with 330 hours. It had never been decarbed before. It ran fine before the decarb (I used the small remote tank with premix and sea foam method). After the first trip out the motor ran very rough at idle. I assumed that there must still be carbon working free so I decarb'd again a few days later. After this decarb I removed the plugs and looked at the top of the pistons. They look like someone sprinkled coffee grounds and oil on them. I guess there still must be junk in there! I plan on doing a shock treatment with Ring Free. Is there anything else I can/should do?

 

[yamamarinetech40]

Re: Yamaha C115 decarb

Do you know how to decarb? Running sea foam and ring free in 'shock' treatments is fine for a yearly cleaning but what you really needed(it sounds) was to get some Mercury 'Power Tune' or Yamaha Decarb(second choice) and follow instructions. Spray it into engine @ 1200 to 1400 RPM, each cylinder for say 30 seconds, then idle down and spray each cylinder full blast till on last one you 'flood' the engine with it, killing the motor....it'll take a little practice to not kill the motor @ idle....let it soak for two hours, then put in water and run the hell out of it....then change the plugs.

 

[JUSTINTIME]

Re: Yamaha C115 decarb

nothing beats water
but u better know how to do it

 

[Reelybless]

Re: Yamaha C115 decarb

I don't know about the 2-strokes, but we used to use water or brake fluid on car engines. Worked like a champ!

 

[JUSTINTIME]

Re: Yamaha C115 decarb

yep water is the best
perfect steamclean

 

[dabhand]

Re: Yamaha C115 decarb

Here are my symptoms: Yamaha 115 94': Motor want to bog down when throttling up to get on a plane. When I flip the electric choke switch, it will power up and go. So, I conclude fuel shortage-do I need to decarb maybe?
Also, how do you decarb with water??

 

[JUSTINTIME]

Re: Yamaha C115 decarb

dabhand start a new thread please