Just read your post, and i also had a blowing problem (out of the carbs) when i first started and ran my 350. never putting it in gear ...just ran the engine. When finally i wanted to test ride it and put it in gear , it ran backwards, turns out, due to my carelessness and enthusiasm, i did not have the timing correct off of the crank gear and the big timing gear that is rides on. Maybe yours is not as 'off' on the gears as mine was, but it was off quite a few cogs on mine. I can only suggest a guess as to the way mine was when first getting"things in order" well, good luck hope you get it going :-) bsforever