[C320-list] Transmission Reduction Ratio for Perkins M30

[P.F. Ross]

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