Power loss 2012 rhino

[jimclemjr]

Did it look like the plug was coated with carbon? Was it tightly threaded? If it was looking really rich you might think about some fuel additive to clean the carbon deposits, I think Yamaha makes something that is supposed to be a top shelf product. Also maybe think about type of fuel you are using. Sometimes a higher octane fuel will not provide as good combustion due to lower volatility, leaving behind the deposits. Use the Yamaha recommended octane level if you're not, and see how it does. If in doubt you can always pull the plug and use a borescope to check the top of piston.

[PArhino]

Thank you for the comment very good advice. I pulled the plug and yes it had quite a bit ofcarbon on it. Also when I pulled the plug, it wasnot very tight. I tightened it to what I thoughtwas the torque spec before. Maybe wasn't correct? When I putnew plug in I tightened to 10 ft/lb.
Also I always run 93 octane with fuel stabilizer, based on what you said I thinkI'll change to lower octane. Any suggestion as to what fuel additive would begood to remove carbon build up?

[PArhino]

Any idea what factory torque is for the spark plug? Local dealer said 9.4ft/lb

[jimclemjr]

No idea but 10# sounds about right. I always use anti-seize and just turn it till I feel the washer start to crush. Of course that is just with a new washer.
I saw something recently on a carbon reducer and thought it was yamaha but not sure. it was a Youtube vid with a scope look inside of cylinder. One of the best I have seen is a motor tonic called Kreen by Kano Labs in Nashville. You can order direct. I have used this stuff in oil and in gas. They say it is a carbon attacker, but do it gradually as suggested cause you do not want to be creating chunks that will interfere or clog.

[PArhino]

No idea but 10# sounds about right. I always use anti-seize and just turn it till I feel the washer start to crush. Of course that is just with a new washer.
I saw something recently on a carbon reducer and thought it was yamaha but not sure. it was a Youtube vid with a scope look inside of cylinder. One of the best I have seen is a motor tonic called Kreen by Kano Labs in Nashville. You can order direct. I have used this stuff in oil and in gas. They say it is a carbon attacker, but do it gradually as suggested cause you do not want to be creating chunks that will interfere or clog.

Thanks for the info I appreciate it!