HELP!!!!

I have the YS 63 engine and can't get it to idle without becoming too rich and quitting. I have the low end screw as lean as i can get it and it still over loads. Is there anything else I can do?

I'm running the 20/20 fuel it recommends and a 12x7 prop. If i can't get this running I'm going to send it in to YS for repairs. From all of the complaints I've seen about this engine, maybe I should just sell it and buy a RELIABLE OS 70 surpass 4 stroker. I have it on a ultra stick 40 and a stick is meant to be flown low and slow! I can't fly it around the way I like without having the engine quit. What do you guys think?