Hi I used a drill to start with because the 90 cspec viper kept killing my starters. the problem was the waste fuel oil out of the pipe ran back into the head and flooded it so now it rests on its side after each flight and i store it on the wall of my shed tail down and that keeps it drained. I now I have a dynatron on a pair of 14ah 12 volt batteries wired for 24 volts. and it works well. my other 90se has a sz 91 and its a kitten to start..... the problem i had was not the blades hitting me but the boom spinning round because i had the blades in my left hand and the starter in my right and it was on the bench so their was nothing to stop the boom coming round and hit me in the ribs. oh and i did not have a shirt on, well it was hot, so the boom support bracket got me in the ribs. lol all part of the fun of rc heli s
