I had the same problem with my saito 150 kicking back when I used a starter on it. The way I overcame it was to use a Higley Alum nut and a dubro alum prop nut. I threadlocked both and made sure it set up overnight before going out to the field. I now wear a glove, and hand prop it.

With the plane secured (I use a couple of padded spikes in front of the wing) and the glow ignitor off, I go to wide open throttle and cover the exhaust port, and give it a few flips. You want the fuel to flow pretty freely out the exhaust.

Then go backwards against compression one flip, to make sure its not hydrolocked.

Put on a leather landscaping or welders glove (I'm turning an apc 17/6 on mine), plug in the ignitor, and flip it backwards against compression. Not too hard, but enough to make the prop flip back in the normal direction by itself. Mine will usually turn over on the first flip doing that. By placing your prop correctly, you can hit the "hard spot" in a way that your hand willl be clear if it kicks back or turns over.

I absolutely refuse to use a starter on my saito, simply because I got sick of the spinner/nut/and prop flinging at me.

Hope this helps,
Steve