[C320-list] Transmission Reduction Ratio for Perkins M30

[Jeff Smith]

Frank,

Perfect. Thank you for the link. I live four hours from the boat so I can’t
easily check. Now I see it will have the ratio stamped on a tag on the
transmission.

Jeff

On Wed, Oct 27, 2021 at 8:56 PM P.F. Ross <pfrstl at gmail.com> wrote:

> Jeff,
>
> There is a Hurth owners manual on the 320 website here:
>
> https://c320.org/filemgmt/index.php?id=130&query=hurth
>
> I recall seeing this nameplate on my tranny but don't remember what my
> ratio is offhand, it is dark now but I will go out and check in the morn.
> I also have the M30.
>
> Regards,
>
> Frank Ross
> Beta Wave #206
>
> On Wed, Oct 27, 2021 at 2:48 PM Jeff Smith <svsailmates512 at gmail.com>
> wrote:
>
> > Can anyone tell me how to determine the transmission reduction ratio for
> a
> > Perkins M30? Watching the conversion about the right prop, I emailed PYI
> to
> > find out what pitch I should set for my prop and to confirm my settings.
> > They said it is a function of prop diameter and the reduction ratio. My
> > manual says Perkins M30 has either 2.05:1 or 2.73:1. I believe I have the
> > latter but I want to confirm before I haul the boat to change the prop
> > pitch. The Max-Prop Classic has two settings and I now think I missed
> each
> > setting by one tooth, causing my prop to have a 14 degree pitch instead
> of
> > the recommended 24 degree pitch.
> >
> > Thanks,
> > Jeff
> > ’94, #121
>