600bft above, did you check your wiring? Change spark plug? Choke working properly? Proper compression? Flow of gasoline not impeded?I got a great running gt-5 been using last 4 months daily and went out this morning to go to a job she fired up then quit. found no spark a magneto not within range ohm reading and changed it. got spark now still no fire. pulled carb checked all the jets for clog all good just wont fire for me. from running perfect to FU today how nice! What carb you have and are you sea level?
Why woukd rich cause lurching? I went to a 77 and it was 4 stroking like **** and didn't even move. I've tried every size jetyour probably running way to rich. if nothing has changed since you moved it over, then your float is stuck, you have a bad needle valve in the carb, or you need a smaller jet. or you muffler is clogged, port, gasket in the way of a transfer, something lodged in your intake, piece of debris in you jet. bout all i can think of at the momment, but spudder is rich, dragging back like someone killed the gas an when it gets to a certian point it races back up, thats lean. if it slows down when it gets hot, you are lean. i can run flat out till i run out of gas on most of my bikes. long as air is moving, their are happy to push.