just fixed 1 for my brother, i took plug out & cleaned it up, took air filter washed it out, when it starts let it run a couple of mins to warm up before u pull trigger. the scew is for the ideling if it tick over ok then it does not need ajusting. ps it is more likley u are flooding it, as the choke is on then pulling trigger lets even more fuel through.
trev
June 2010