Im playing around with a 27cc stihl engine for a boat and after some searching i noticed that some of you guys on here are using that engine so i thought id post this here. Anyway I thought id try and lighten the flywheel a little, wasnt going to go too crazy, just going to cut the fins in flush to the rest of the flywheel to reduce some drag. So I went ahead and done that and when i got the fins cut down, i noticed that the casting was out by about 30 thou, meaning i had about 30 thou of fins left on one side when the other side was clean. So i decided to take another cut and face it all off the same thickness and i ended up hitting something steel. Im guessing its a part attached to the magnets to hold them in place. Once i hit this i stopped, so one side now the fins are still noticable but their almost cut flush.

I'm kinda nervous now about this thing comming apart. Alot of you plane guys run lighter flywheels right? How dangerous is it maching them down? Heres a pic of my flywheel (steel part is between the holes in the lower part of the flywheel), what do you guys think? Should I try and pick up another one?