My 130hp 2 stroke motor's engine warning buzzard started today. Water was coming out of telltale, no smoke, and I had plenty of oil. As soon as I reved up above 2700 rpm the buzzard would quiet. I was able to get home at 4000 with no problem and no buzz. In past when the warning buzz came on it would not go above 2000 rpm. The buzzard sounded as soon as the rpm went below mid 2000 rpm. Ideas?