More than likly flooding the engine. It happened to me too. was wondering why it died once i started to hit 3/4 to full throttle.
Too much fuel!! engine get too cold when that much fuel is added and cannot egnite future fuel. hence stall.
if you wanted to test the theroy you could find a way to strap your glow starter on and try reaching full throttle again.
lmao. not what i suggest. lol. just my retarted friends idea to keep maximum oil cooling while breaking in a engine.
over kill in my books.