This is exactly right. Two stroke engines operated regulary and often WILL last a lot longer and this mainly affects the crank.Morph wrote: The biggest irony is engines used more often tend to be more reliable - .
This has been experienced in just about any flight school that I am aware of.
The reasons are of course simple.
Oils don't stick to metal for long and will run off. How long this takes depends nearly exlusively on the oils viscosity. Once your metal parts are exposed to air (and there is lots of this in the crank case and it is well ventilated unlike that of a four stroke) corrosion sets in. Most of your crank does not care about that - but the bearings and in particular the needle bearings in your piston will rust given the slightest chance. A tiny drop of water condensate is all it takes to get the process going - you get what is called "pitting". Really just a tiny rust spot. Once the bearing gets moving, that little indent starts to increase rapidly as it gets hammered every time it mates with the bearing race. This quickly destoys the bearing and it crumbles due to work hardening (Like a smithy overdoing his hammering).
So - easy to fix, fly as often as you can (now you have a real excuse) and use a nice high viscocity oil. Sorry folks - that excludes sythetic oils or semi synthetic.
This applies to any two stroke, not just Rotax.
Rainier
CEO MGL Avionics