<div style="text-align: justify">Mr. Cox hs a very good point - corrosion is a not unlikely issue.It's amazing how rapidly it can set in, too. That's why I always rinse my engines after running in Varsol (inside and out) followed by some time in the ultrasonic cleaner in methyl hydrate (eliminates the "diesel aroma"!). Then the after-run oil (I generally use air tool oil).

The thing to remember always is that the smaller the bore, the greater the effect on compression of any wear in the piston/cylinder set-up (whether through running wear or corrosion makes no difference). This is because the circumference of the piston or contra-piston(the leakage "pathway") varies with the square of the bore, while the volume of gas above the piston varies more or less with the cube of the bore (assuming near-square bore/stroke dimensions). So the volume of gas that's there to be leaked is reduced far more rapidly with decreasing displacement than the pathway through which leakage can take place. The result is that a given linear leakage rate along the piston or contra-piston circumference drains the compression off far more rapidly as you go smaller. Hence fits become more and more critical, and the slightest slackening of the fit can lose you all of your compression.

So with the smaller engines, it's more critical than ever to do everything possible to avoid either corrosion or running wear. I've always found that the tiny engines don't last as long as their larger brethren, and I'm sure that this has a lot to do with it. If you must run them, use plenty of good-quality lubricant and keep the engine clean and free from fuel residues at all times!

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