I may be wrong, but I believe that the methanol is what attracts water and then forms rust...just look how quickly fuel craps out(even FAI fuel, no nitro) if you leave it open. I don't know if that last part made sense, but oh well. Justin, I was figuring you could ask the engine gurus if 2-stroke moto lube (syn. blend) works ok as after-run, that's all. I think shoehead nailed it. The most important function of an after run oil is to displace any water from the internals and form a protective coating. It's supernice when it burns off more or less cleanly too, so it doesn't foul the plug. After a bit of searching, it appears we're flagellating a deceased equine with the general after-run oil question, but I haven't turned anything up so far as to the appropriateness of motorcycle 2-cycle oil as after-run lube.