Marinette Boat Forum

FYI on todays project. I had a carb start idling crappy on the port motor late last fall and I decided to wait to spring to go through it. About that time, and I noticed it again this spring my transmission on that same port motor started getting real noisy and sounding like it was asking for something major. Fluid was not very old, clean and fresh looking. One of my best boating friends has a Chris Craft Aluminum Roamer and when I mentioned it to him he said it was just my crappy idling carb causing it to rattle as it pulsed, loading and unloading the transmission gears and components. He had seen this exact same thing in their boat and the previous owner was unable to fix it with transmission rebuilds and had it idled up to mask the problem. His turned out to be worn exhaust seats in his Ford 427 heads and mine appears after I rebuilt the carb to have been my carb issue. A non smooth running engine can transmit pulses into the transmission and then through the aluminum hull and create quite a bit of racket. I reinstalled my freshly tuned up carb this afternoon and it started instantly and idled smooth as silk again and was quiet in gear tied to the dock. Looks like he was spot on. I get to thinking I know about everything there is to know about cruiser boats after 50+ years on them and then somebody teaches me a new trick out of the blue. Man I love it when that happens !!! Means I am not completely an old dog yet.

I recall a similar occurrence with our 318's. When the engines were stumbling at idle, the trans started rattling as if the nuts, bolts and gears inside were loose. Smooth idle cured it

Right! The torsion coupling (looks like the center of a car's clutch disk) will make a hell of a racket if the idle isn't smooth. That can damage the thing, so it's good you don't let it continue too long.

Jeff