I have a 1954(?) NAA or 600 the best I can tell. I decided to rebuild the carburator since I've been having trouble starting it even after changing the points, condenser, rotor and cap. When I removed the air tube going to the air filter gas poured out and it looks like the floats stuck. I bought the kit and started to do the rebuild but I'm not able to remove the seat. I've literally done everything including drilling out the seat. I don't want to go any bigger or I"m afraid I'll mess up the threads. I'm not into the threads but to close for comfort. I even tried an easy-out without luck. I went to town this morning but can't find a tap the right size. I'm getting different opionions on the type and size of the threads. Can anybody tell me what the threads are? THANKS in advance :?