I'm Experimenting With Minus 2 Sportmasters

On A 1989 No Step 38 Fever With 650 Blower Motors

The The 5 Blade P5x Hydro's I Decided To Try Are

Slipping 22% And Took My Old Boat Speed From 80 Mph

@5050 Rpm With Bravo One Standard Height With 26

Hydro 4 Blades, To 70 Mph Gps @5100 Rpm With The

New Short Drive With New Prop . Has Anyone With

Similar Boat And Drive Found What The Correct

Spacing Might Be Thanks For Any Help

something's not right, you may have to try spacing down 1" & see what happens, unfortunately there a too many variable's to give you a cut & dry answer. From what I understand most have experienced an increase in top speed with the shorty drive (but every boat is different) You may want to try as many prop combo's as you can. Keep testing.

Ya...
We got the same problem...
It's the X dimention.

Did you try the 26 4 blades just for a test.

the sportmaster is 2-3 slower in general, against say an imco. at 80 you are not going fast enough to take advantage of the effeciency of the surfaceing design of the sport master. going down may in fact increase your speed due to giving the drive more leverage to lift the bow thus diminishing wetted surface of the bottom.
try a 1/2 spacer with the same prop with maybe some cup added.

hope you find the sweet spot.

Can't they are fixed hub for bravo ones smaller prop shaft.

80 is my starting point before changing drive height
and intercooling and 5 blades hope to make 90 when dailed in.

what x d did you try spacing for ?

I'm going with a 1 1/2 inch spacing

Note : I got side tracked while testing and working on boat

that my port transom plate water passages rotted out so motor getting pulled to replace it

Owners of older 1989 models keep an eye on them if your in salt water like me !
\nwhen its done will have new test and info ,

running new blower pulleys; new pickups for inter coolers water pressure , 1 1/2 inch drive spacers looking for close to
90 on the gps will let you know!

[QUOTE=Nauti By Nature]

that my port transom plate water passages rotted out so motor getting pulled to replace it

Owners of older 1989 models keep an eye on them if your in salt water like me !
[QUOTE]
I had that same thing happen with mine.

Motors In Drives on going back in water tomorrow.