starters?
locoworks, I understand the problem.
When things get serious, I drag out a serious starter. I converted this one from a Nippon Denso starter that was used on a Mitsubisi (sp) V6. The conversion consisted of removing the gear which engages the flywheel, taking the front end (the end next to the engine) apart and removing the spring which retracts the the gear then reassembling the front end. Next I drilled a half inch hole in the Miller R/C Products 3" drive cone to match the output shaft. Then a set screw hole (10-32) was drilled in the side of the cone. Next, several washers were put over the output shaft, the shaft pulled forward, and the cone installed. They shoulder against the output bearing on the starter and the back of the cone. If you don't pull the shaft forward then it will not be engaged. The Campbells soup can was used as a guard to keep the socket head set screw from knocking the c**p out of my hand.
Over all this starter is better for large engines than the Dynatron on 24 volts because it has far more torque, due to the gear box, at much lower speed. Of course it works on 12 volts. I haven't tried it but feel that it would turn a 240cc engine over without even breathing hard.
Ken