Engine cleaner

[Debra]

Hi Clarence,

I am happy to see you are back writing a column. I subscrebed to MAN just to get your column.

I have a question. I picked up a Moki(Mark) 135 at a swap meet at a good price. The piston in it is almost black. The seller said it was caused by running a high castor oil content fuel as called for in the instructions( Omega A fuel with 2 oz of castor added).

Will this hamper performance? Should I dismantle the engine and try to get it off?

Thanks
RK

Dear Mr. K,

When you use a castor based fuel you can expect the piston to turn dark, especially with a ringed piston engine. This normally doesn't hurt anything unless a loss of power is noticed. Go to the auto parts store and get a can of fuel injector cleaner. Using a fuel bulb, dribble the injector cleaner through the engine while it is running. Then add an ounce or two to a couple of tanks of fuel. Not all brands will mix with model fuel, but Gold Eagle Fuel Injection Cleaner, Snap Fuel Injection Cleaner, and Chevron Pro Guard are good.

Yours,

Clarence Lee