Its all how you start it with a Roto Start.

You can just push the button on the rotostart and keep it pressed until the engire fires up. You need to learn how to pulse it, just like a Pull start only turns the engine over a bit.

Hold the button for 2 seconds max. Then stop, and pulse it again. Thats the right way to start it. I've gone through 2 gallons of gas so far and I'm still on my original one-way bearing.