Hi Guys,

I;ve just bought a sullivan dynatron starter. First time i used it on a conventional ccw engine the ali starter cone cup unwound itself and promptly flew off. I've refitted it several times and tightened the locking nut down but still it unwinds. Whats the point of having all this starting power if it cannot be transfered to the engine!?! I'm only using 12v and trying to start a webra 91AAR heli engine.

Does anybody have any tips to make the conventional retaining method more secure?

Try adding a thread locking liquid i.e. Locktite. After adding it and tightening the nut, let it set up for several hours before using it.

Is there enough room on the shaft to add a second nut to lock the first one? You could also try a star lockwasher, and put some threadlocker on the shaft when you tighten the nut down. Torque it good. I have used the same starter for a couple of years, starting a 41cc gas engine, never had the cone come loose.

try a lock nut the type with a nylon insert

I too recommend a double nut config if possible. Ive had to resort to this, works just fine.....unlike my flying abilities.