I think the problem is that you NEVER choke it with the ignition off..you will flood the engine/plug..once the plug is wet you can flip till the cows come home..I think this is your problem..the only other problem I had was when the low end was to lean..

I put the choke on and the ign on and after 10-12 flips it starts then dies..then 3 more flips and it starts