Ducati Owners Club of Victoria

SPARK PLUGS : TECH TIP

Ducati motorcycles have short thread spark plugs, locating into an alloy head. It does not take much to strip a spark plug thread requiring either helicoiling, or a new head. (Very expensive and a lot of work.)

Inserting the plugs by hand until they seat is the safe way to go. If you can't seat them by hand, find out why before you go for the tools. Maybe the plug has a deformed thread or dirt in the grooves or the sealing washer has dropped down etc.

Only use a plug spanner to nip it up. Most people over tighten plugs so don't pull too hard on your 8" extension. (You'll go blind!)

Lubricating the threads can help but oil tends to gum up with the heat of the engine. I use a product called "Never Seez" made by "Bostick". This is some sort of graphite impregnated compound which can withstand up to 2,000 degrees C. Even at extreme temperatures, some of the lubricant remains, making it very easy to remove the plugs.

I have used this stuff on exhaust flange threads, exhaust pipe clamps, spark plugs etc for several years and have had no problems with gummed up threads or removing them at a later date. I think most locktite stockists will carry the stuff but I've had my tube for so long that I can't remember where I got it from!

Original article by Peter Shearman, February 1983