Ok, no video yet but a day of poking and prodding reveals the noise is coming from under the flywheel area. I’m starting to think what I’m hearing is the reed plates flapping. The motor starts and runs beautifully and revs up great. Going in and out of gear does not change the sound, so that’s why I’m thinking reeds. Putting the air silencer box back on and the cover quieted it down as well. I have it’s 30hp evinrude twin..although a bit newer right next to it on the rack. Tomorrow I’m going to fire that one up and do a comparison. Will keep you posted fleetwin and chris p.
fleetwin US Member - 2 Years Replies: 4737 Topics: 46
Good, I’m glad you didn’t rip that gearcase apart. Like I say, those engines are normally pretty noisey. Your newer 30hp is probably quieter than the 1977 35hp.
Sometimes these engines have a bit of a "ringing noise" as well, never really figured out just what that is. But, I would definitely pull that flywheel and look for evidence of magnets rubbing on the components. Probably a good idea to remove the mag plate, clean and relube the bushings, replace the plastic bushing: 322435
There should be a plastic threaded/spring loaded screw that threads into the lower throttle gear under the vertical throttle shaft leading up to the mag plate. Screwing the spring loaded knob/screw in or out sets the idle speed. Unfortunately, these plastic screws are usually broken/jammed.
OK, just a stupid question here. Why not replace the nylon screw with a stainless one with a nylon cap? I’m sure there is a reason… But like I said, This big a motor is new to me.