I used a Dewalt 14v drill for a couple years starting a ZDZ 50. Works great. You need a large cone and insert then drill out the attatchment hole for a 3/8" bolt. I quickly wore out smaller bolts. Cut the head off the bolt for the drill to clamp the smooth shaft. Clamping on the threads will cause the chuck to dig in and let the cone come loose. You don't want that to happen while starting a motor. Couple lock nuts and yer done.
Your drill spins about 1600 rpm and the engine will idle about there too so no problems overspining the drill.