First suggestion would be to call Comet. Can’t see how the key would fall off if you can’t get the starter nut off. Using the Comet clutch tool, secure the clutch and use an impact wrench to loosen the starter nut. Next use the puller. See this post for additonal help.http://ekartingnews.com/forums/topic/stuck-hortsmen-2disc/
LAD Specialties customer / tony kart / rotax / kt100
Thank you everyone. I finally got my starter nut off. The crankshaft thread was in really bad condition. And I imagine that the the starter nut couldn’t get off because off how messed up the thread was. Now I just need to send my engine somewhere to get my new crankshaft installed.