use an odonell 077t plug or an os p-3 other things to try;make sure idle gap is .7-1mm. then set hsn 1/2 turn in flush,the lsn 1 1/2 turns in from flush. should fire up and run fine. if it continues take out hsn and blow through the line that go's to the pipe. look for rubber pieces to come out of the top of the inlet hole. I hold a paper towel underneath it to catch fuel debris. another thing I do is plug intake and exhaust with thumb/finger use 2 feet tubing,hold engine in water and blow into fuel inlet and really see if you have a leak and where it is coming from. you'll be surprised at what you find leaking. You don't need to try and blow the seals out of it,just enough to find leaks.