Just for grins, I cut off the front shaft of an old Sullivan starter. It was chucked up in a Makita 18 volt drill. It started 42 cc poulin with no problem. It had plenty of power on high speed. The mass of the battery keeps it really stable. This is now my standard starter for all of my engines. This can't be the first time this has been done?
Anyway , you might try it.
motorhd