[C320-list] Vibrations at certain RPM Range

[Arthur Gates]

My stern ladder rattles against the top of the stern pulpit at times. 
#186

Sent from my iPhone

> On Aug 6, 2019, at 10:38 AM, John Meyers <jcmeyers7 at gmail.com> wrote:
> 
> Starting about 3 weeks ago the boat is making a loud racket when the engine
> is revving between 1500 and 2000 rpm. mostly in the rear of the boat but I
> cannot pinpoint the source. This occurs both in gear and in neutral so not
> suspecting shaft alignment. I suspect that it is some harmonic thing. All
> motor mounts look good and solid and well attached with over a quarter inch
> between the metal parts. I have check both feeling and/or removed just
> about every thing in the lockers like spare prop, spare anchor, propane
> tank, and other items that might be shaking while the noise is occurring. I
> have felt the fuel tank and engine and nothing feels different than when
> the noise is not noticeable. I have even gone below the boat and felt the
> shaft prop cutlass, rudder and all seem solid. The shaft and cutlass
> bearing were replaced a couple years ago. I have checked the steering
> mechanism.
> 
> To explain the noise/clatter it sounds like a loose hatch, door, or
> equipment is shaking.
> 
> At low revs and higher revs the noise is not there.
> 
> Has anyone ever had this problem or know someone that has/had this problem?
> 
> Thanks for all your help in past, present, and future. I rely on the
> questions and answers this list provides.
> 
> John Meyers
> Wind Chime 1997 #406
> Muskegon, MI