I have a 1991 Sea Ray 225br. 454 Mercruiser (carburetor, no fuel injection) with Bravo 1 drive. Took it to Avalon, ran great. On the way back, about 11 miles from Avalon, 26 from Dana Point, running around 3200 rpm, it sputters a bit. I lower the rpm, seems ok, take it back to 3200...