Here's my attempt at converting this Poulan 42cc using a portion of the saw case. This way, I keep the engine, flywheel, and magneto in it's proper position. I still have to get a prop hub and mount it to some sort of test stand. I think more trimming can be done to the case near the "chain oil" portion of the saw case under the magneto. However, I won't do any more trimming until I actually get it running with a prop. I'm not sure how much I can trim away around where the magneto mounts, because I'm afraid of weakening this area. I'm not concerned with saving every last ounce of weight on this engine right now. My goal is to simply convert it to an airplane engine using the original ignition. If anyone has ideas or comments on my approach to this conversion, please let me know.