i have a 2001 9.9 4-stroke yamaha carbuerated motor that is extremely hard starting and after running an hour or so wants to stall out(and usually does). this motor has at the most 8-10 hrs on it. if i spray starting fluid in it , it will start, but again after trolling for a while it will stall out. without the starting fluid it will sputter and start but not for long. any suggestions?...Thanks in advance. captn-tin