take the starter off and just block the hole with a custom piece... or just take the starter motor chain off and it will get rid of that irritating sound when you kick it.
I have a Electric start engine before and have also tried to convert it but it is not possible as there is a massive gap/slot type thing built into the engine for were the back piece of the magneto cover slots into and if yoy trie and put a normal type flywheel and cover you will be left with a massive gap inbetween the engine and the end of the magneto cover and crap will get in, i did the exact same thing as dambomb did and used tin for the flange thingy