Hi Lee,

It should just be a case of getting a pull start unit that replaces the crank case cover on the engine. Unless you also need to get amodified crankshaft,

If starting with the pull start you may need to loosen the glow plug slightly when starting to help you turn the engine over. Also fitting a pull start can add a bit of resistance which will slow the engine down. Not sure if it would be noticable though.

Rich