I have the two handled Megatron starter by Sullivan. I use two 12 volt batteries, 18 amps each for a combined 24 volts out put. This combo is really hard to beat, but the total cost will run around 200.00 with the batteries.

I purchased the Megatron to use on a Fuji 50 flywheel generated spark engine. For me, I had problems flip starting this engine. There is definitely and art form to the flipping process. After giving out with the flip starting thing I tried using a drill for a starter which actually worked, but not very well. The problem with the drill I used was that it wouldn't provide the rpms. needed to get the starting spark desired for a gas engine. The engine would start using a drill, but I also noticed that once the engine fired the engine wanted to turn quickly to a higher rpm. than the drill, so the drill actually became a bit of a problem. Maybe a higher speed drill would work, but this is what I experienced with a 1/2 " drill. Better than flipping, but the Megatron is definitely the way to go with a flywheel generated spark engine. Huge difference after the flipping and drill experience. It started the Fuji without any hesitation. Some guys have no problems flipping these engines, but I did. Just sharing my experience here.

If you haven't already purchased an engine, you might want to consider an engine with electronic ignition. The cost will be about the same as an engine without electronic ignition and the added cost of the starter and batteries. Electronic ignition makes the engine easier to flip start. Conversely, there are obvious added personal risks with flip starting vs. using a starter.

This is what I learned the expensive and hard way. If you have to invest in a high torque starter and the engine you are using requires the added power of 24 volts then the Megatron by Sullivan is a great choice.