[snopro1978]

Just spent my first weekend on the water with my 1995 Mariah. I am very pleased. I was wondering if anyone is running a 23p prop on their boat with good results. I currently am running a 48-78122a40 (21p). It performs well but RPMs get to 5000, a little high from what I understand.

[mikeyt]

I think there is something wrong with your tach if you are reaching 5000rpm with a 21" pitch prop. That pitch should have you down around 4600 at WOT. Access the backside of your tach & give the little dial a spin a few times before resetting it
at "6 cyl". The other issue may be that your prop has been rebuilt at some point & its no longer a 21" (it may be less) so that might account for your high rpms.

All that said, we do have one member here who says he successfully runs a 23" pitch prop on a '94 or '95 Barchetta 180 with the 4.3. For most of us though a 21" is the maximum and its only used for cruising.

[snopro1978]

The prop is pretty beat so you could right about the pitch being off. Do you know the name of the member with the 23?

[mikeyt]

I do. "SEMIjim" is his name and here's a quote from one of his earlier posts...


Btw: We're running a 14x23 prop on our '94 182 Barchetta with the 4.3L MerCruiser V6, 4 bbl. carb and she runs fine. Good hole shot and, IIRC, 45 MPH at 4800 RPM WOT.

Jim

Note though that his situation & his use of a 23" prop is unique on our site. Probably 75% run 19" pitch 3 blades and the balance run either 20" 4 blades or 21" 3 blades.