So run the TZ crank?

Thats the thing about modding an engine. You void the warrenty. You might be able to send it in and have them not notice it.

You could always trade someone a new TZ crank for a used TZ crank, and keep that around if you ever have to send it in.

The guy I sold my 30vg to cut off the starting shaft pin from the PS crank, and put a bump start backplate on it. Something went wrong in the process and the engine completely lost compression. So he sent it in WITH the modified crank. This was originally a PS engine, and he got a new bump start version back.

Course, I'm all Nova'd out with both my RC's right now.

OS isn't too picky about their warranties.