91 225 hp precision blend

[Jrprochbass]

What's the best way to clean carbon of the cylinders. I pulled the spark plugs out and five of them had carbon on them.

[Sequoiha]

Yamaha Ring Free, shock dose,, and make sure your oil pump link rod is adjusted properly,

[rodbolt17]

combustion chamber cleaner works well.
I would be more concerned about the plug with no carbon than the 5 with.
what cyl did it come out of?

[Jrprochbass]

It was on of the bottom cylinder on the passenger side.

[Sequoiha]

a dry plug on any cylinder is a bit of a concern especially a bottom one. might want to check your oil delivery system, check valves on the oil lines, also look for water ingestion, could be steam cleaning the cylinder which will lead to failure..

[rodbolt17]

a leaking pump diaphram will fuel wash a plug.
a clogged main jet can lean clean a plug.
a certain amount of carbon on a two stroke is very normal.

[Jrprochbass]

Will Look into those things. Motor is winterized till mid march or early April.