Top speed on a Diplomat??

[85diplomat]

Topped out at 59.6 with a 21 aluminum( on GPS, half tank ,4 People). I'm running about 300 hp(tweaked 5.0), wondering if a 23 stainless would be a big jump or is the transition from aluminum to stainless offset some of the pitch. What should I be looking for?Hope to get out one more time by myself, run the tank low, and let her scream!!
Still runs 4800 w/21 p

17' checkmate "Cheap Thrills"

 

[85diplomat]

Topped out at 59.6 with a 21 aluminum( on GPS, half tank ,4 People). I'm running about 300 hp(tweaked 5.0), wondering if a 23 stainless would be a big jump or is the transition from aluminum to stainless offset some of the pitch. What should I be looking for?Hope to get out one more time by myself, run the tank low, and let her scream!!
Still runs 4800 w/21 p

17' checkmate "Cheap Thrills"

 

[175checkmate]

IF you go to a S.S 21p the rpm will be slightly lower. The aluminum props tend to flex, gaining rpm and loosing speed. I would start hunting for a 21p stainless, something that provides alot of bow lift.

1975 Checkmate Tri-mate 2, 2.4 200+ / Sky jacker 6" plate / 25p Laser 2 prop

 

[85diplomat]

any suggestions?

17' checkmate "Cheap Thrills"

 

[JW]

Start with a 21" Laser II that hasn't been worked (factory original). That's always a good prop to start with on a 'Mate I/O with small block. With your stated power you'll probably have to also try the Mirage.

Checkmates owned: 1995 Pulsare 2100BR/1995 Mercury Promax 225 2.5 EFI. 1995 Persuader 183/4.3 LX V6. 1992 Pulse 171/1992 Mercury XR6 150 hp 2.5 liter.

 

[85diplomat]

Thanks... anything to get a few more mph!

how do you feel about 4- blades

17' checkmate "Cheap Thrills"

 

[175checkmate]

4 blade = killer hole shot, so so top end.
A 3 blade will be faster, due to less blade area.

1975 Checkmate Tri-mate 2, 2.4 200+ / Sky jacker 6" plate / 25p Laser 2 prop