2003 Honda Rincon 650 won't start without blowing air hose through the carb intake. Plug is black and sooty. I know its running rich. It had a 160 main jet in it.....stock is 148. I've tried changing the jet and needle height, but no luck! If I blow air into the intake on the carb, it will fire right up, but won't idle and it seems to have a little miss. I just bought the bike and tomorrow was suppose to be my first day to ride it. I'm assuming that it had a larger jet for the HMF pipe and the fact that it came from lower louisianna. It has started everytime I've tried to start it, but today I started it and moved it about 15 feet and now I have this problem!!!!!