My Mako 195 DC with a 2000 model Merc 150 carb motor seems to run quite well, but makes a loud distictively different exhaust sound while running at 3200 RPMs. This is my first Mercury outboard, and I don't know if this is normal. The engine starts and runs well, and propels the boat to a GPS top speed of 42 MPH. Above and below 3200 RPMs, the engine is fairly quiet. Any thoughts?
