Merc 1150 rough running

[fishdog4449]

After finishing the trigger job on the 1150, tried to fire her up. She fired right up but ran really rough and died after a few seconds. Then more choke, crank her and she would fire back up for a few seconds, again running very rough. When I rebuilt the trigger, I made marks on the belt, flywheel pully, distributor pully, and flywheel and it all lined up right, so I didn't think it needed to be re-timed. Is this something I can do myself, or should I take it to a mechanic? BTW, The manual comes in tomorrow. Also, the idle screws (on the right side of the carb, I think they're idle screws...) were only set 1/2 turn out. Would that have anything to do with it?
Maybe the fact that I was using year old gas had something to do with it, I'm getting some new gas today.