Yamaha 115 Power Loss

[JSP]

Well, I committed the sin of not boating for the last year or so. (I did stabilize the fuel, and then ran the carbs dry on my last outing though) Still, the 1996 Yamaha 115 runs a little rough at idle and will only make full power briefly after choking. I assume the carbs are gummed up. My question: Has anyone used a spray product which will open these orifices and ports back up? If not, and carb tear down is necessary, can I do it, or is best left for the pros with their tech books and calibration experience?<br /><br />Thanks for the feedback!

 

[BlackKnight755]

Re: Yamaha 115 Power Loss

My guess is that the carbs have "varnished". This is when the tiny amount of gas and oil completely dry, leaving a dryed crust-like varnishy residue on the inside of the carb. I know of no spray on or in that will solve your problem. And if you feel comfortable doing the job, go for it, but remember there are some adjustments that need to be checked after the job is complete, ie: idle speed, air to fuel ratio, etc, so maybe you can do the cleaning job, but let the boat pro do the adjusting... good luck.

 

[bobwoodfield]

Re: Yamaha 115 Power Loss

I have the same engine, and left it standing for 6weeks.On launching the power was way down and I suspected carbs. Cleaned everything, but still down on power. Checked plugs and some water on bottom R/H plug. I suspected a head gasket but on pulling the head off a small hole had etched through from the water jacket into the combustion chamber.We are using the boat in the sea and always wash through with fresh water for 10 mins.Still after 14 years use not bad.A new head solved the problem, and I should now check the L/H side for corrosion.Just a thought.Bob.