While getting my bike ready for winter, it seemed like a good idea to coat the cylinders with WD 40. I sprayed them down put the plugs back in and spun it over. It strained on the first crank and then was OK.
Thinking what a dope I am, how much fluid comes out and how long did I spray it? Checking the can, there was a measurable amount of liquid that came out in the 3 second burst I did. The big mistake was putting the plugs back in and sealing the cylinder. Long story short, it didnt hurt it but the possiblity is there.
Spin it with the plugs out.
MikeM

 

If it was me..
I would use oil insted of wd40 50 wt and spin it over with the plugs out to coat the cyl

 

Here is a little bit of info for you, WD40 is a lousy lubricant and maybe OK for helping to remove rusty or frozen nuts and bolts, but there are much better products out there then WD40 for that even.

 

marvel oil

 

Try using fogging oil in the cylinders instead .

When I boated myinboard boat engine would get a half of spray can of fogging oil sprayed right down the throat of the carb. , with a final full spray to kill the engine .
It must of done its job cause come nextboating season it would sure smoke and run rough for the first few minutes.

I can't say if thats the proper way to winterize a harley , but I have tried it once with no ill effects .

 

If you're worried about winter rust, go to any outboard motor dealer and get "Fogging Oil", made by any number of companies. Boats typically sit for a lot longer than cycles. On carbuerated models, you can spray in directly into the carbs while the engine is running, plus remove the plugs and spray directly into the cylinders. Crank it over a few times (without the plugs, as you found out!) to coat the cylinder walls.

In spring, be prepared to install new plugs, after you start it up. Shine a light down your plug holes and you will see nothing by shiny, rust free cylinders.

Also works excellent for preventing rust in exhaust pipes. Just stick the wand it and spray it around. Lot's of smoke in the spring when you start it up!

WD-40 I would think is the worst thing you could use. It'll do an excellent job of cleaning your cylinder walls bare, leaving them prone to rust.

 

Damn, sniped by high gear! Watching The Hunt for Red October as I typed this!

 

I third or forth the recommendation for using fogging oil instead of WD-40. WD-40 will actually wash down your cylinders and leave them dry. You can use Seafoam as a fogging oil if you want.

My 1985 Chevy powered boat gets a heavy dose of fogging oil when I winterize it. It sits idle for about 5 months and always starts right up in the spring. The boat still runs like new. Fogging must have done it good for the past 22 years.

 

WD40 is more like a solvent.

 

Agree!! Solvents and anything that melts away oil/lubricants have no business inside your engine or any friction device like bearings and such. And, for rusty stuff PB Blaster is the product to use.