ORIGINAL: grecospad
you can also try forcing fuel in it by blowing air with your mouth from fuel line that goes to the pipe
that's just a bad idea.
However if you find that it's flooding (you can tell by the roto-start having difficulties turning) back off the glow plug enough to releae the pressure on the cylinder, with it still slightly opened apply the glow starter, then fire it up.
It will run rough, then screw the glow plug back in while it's running, at this point the motor idle will smooth out.
Follow the rest of the break in procedure and have fun.