Oil has got into the combustion chamber of my HP 470, contaminating the spark plug resulting in a reduction of performance. Tried cleaning the spark plug but gets dirty immediately. The question is how to clean up the oil from the chamber (cylinder?)

M Dathi, October 2008

Check that the oil level is OK.

Start engine and run full speed until the smoke clears. Might take 5 minutes or so.

Replace plug.

If the plug continually oil-fouls after this, it indicates worn piston rings, which will need a conplete re-build to cure.

Are you sure it's oil fouling? If it misses, and produces black smoke (as opposed to white), the problem is fuel related. If it's a carb-on-the-tank model, replace the carb diaphragm.

phil_saunders@bigfoot.com

Phil Saunders, October 2008