Bill if you still have an original Johnson pump
Model F4B-903, the Johnson impeller to fit is type 08-810B or 09-810B. Should be neoprene. Includes gasket 01-42391 but we use an o-ring part number 0.2173.476.
Yanmar part for the impeller is 128990-42570, previously 128990-42200.
Alternative Jabsco impeller is 653-0001.
Hope that helps.
Dennis
'Catalina' #0577. 1999.
> On 11 Aug 2025, at 18:03, Bill Allen via C320-list <
c320...@lists.catalina320.com> wrote:
>
> Way basic question I know, but, there seem to be a bunch of impellers that fit a 3GM30F. We have a 1998 #536. Does anyone know the exact part number for the kit and/or the individual impeller itself I know Catalina Direct has the right part, but, in charging twice the price, they don't list the part number....