Xb-21 props

merc106

merc106

Active Member
Joined
Jun 25, 2008
Messages
81
Points
8
Location
Gainesville
Need some help on props? *What I have is a '12 xb-21 pro sport with a '05 300x *1.75 sporty (allison mods)with a tuner, poppet and Simon throttle body, limiter is 7100 rpm. *With a full fishing load 450lbs two 200lbs men , 3/4 fuel and a full live well with a hydro 28p QIV-X O/T the boat runs 97mph at 7300rpm which is all over the rev. *With four people it ran 94mph at 7200 ( not so well balanced).*
With a 30 et 200lbs lighter load it ran 101mph at 7400rpm (hole shot was better with the hydro)
Mercury wants it to run at 6700rpm for optimal performance on motor.
I have not ran an empty load solo yet because I don't have a prop to do it without killing the engine. *Don't really want to go to 1.62 gears because of fishing hole shot will suck. *Hydro is going to add some cup and take some nicks out of the 28p to get rpm down and then re pitch if need be.

For a strictly top end empty load xb-21does anyone have any insight on props? *Looking for the fast *top end prop not that worried about lower end performance. *I have been told that even a 32p won't get the rpm wear merc wants them and it could handle like crap, That to get to 6700rpm I'm gonna need to change gears. *Maybe I should just get a 2nd sporty for playing

I've owned xb02s,xb03s, and 2+2s and I have always been a hoss guy but not sure if that is the way to go or not. *Any knowledge will help! You can write back or call me at 352-472-7867 thanks ,Bob*
 
xb03fs

xb03fs

Well-Known Member
Joined
Oct 17, 2008
Messages
2,370
Points
48
Location
STL
I have no business guessing really but second gearcase is probably saftest option
 
Last edited:
wc911

wc911

Active Member
Joined
May 12, 2009
Messages
412
Points
18
Location
Lawrenceburg Tn.
Call Todd at Hydrmotive and he can tell you what you need . They have alot of R and D on Allisons
 
GotMyAlly

GotMyAlly

Well-Known Member
Joined
Mar 15, 2005
Messages
4,907
Points
63
Location
Olive Branch, MS
You're running a lot more HP than me, but also got a lot more RPMs to play with. I'm running a 28" Hydromotive X-OB day in and day out. I had a 28" O/T but sold it last year (was all over the limiter) and just now got the same prop in a 30". That's what I plan to run as my top end wheel....but haven't taken it for a spin yet. I ran some over-hubs when I first got my 21. O/T or OB's just run better than over-hubs on these heavier hulls, in my opinion. If you ran stripped, I think a over-hub could work for a one-time top end number, but for anything else I'd rather have more blade area to carry the load.
 
xb03fs

xb03fs

Well-Known Member
Joined
Oct 17, 2008
Messages
2,370
Points
48
Location
STL
just a thought there is a used hydromotive in the props for sale section that could be interesting to try. It also has some of the tail lift taken out which in theory could make it a little faster. I would get Todd's opinion before pulling the trigger. Again. I don't have a 21, I cant run nearly that fast but I like OT handling characteristics
 
GotMyAlly

GotMyAlly

Well-Known Member
Joined
Mar 15, 2005
Messages
4,907
Points
63
Location
Olive Branch, MS
I've got a 21 prosport/250XS. I've got 1.62 gears though. Personally....I think that's the way to go. It's pretty widely known that the higher pitched props don't handle as well. You can always drop back in pitch to help your holeshot on those heavily-loaded days. I've got a 27" X-OB for those days when I have a butt in every seat.

The 21's are already punching a much bigger hole in the air than a 02/03. And they've got a lot of tail lift, which can get hairy on the big end. Running a huge amount of pitch is going to add paddle-wheeling to the list of factors that may contribute to a bat-turn.
 
M

Meyers

Active Member
Joined
Oct 27, 2008
Messages
136
Points
16
Bob...We have seen each other on the water in Rodman when you had the 2+2. I have the White & Black 2+2 with the 250 Pro XS. I have a couple of props that you might want to try. I have a 30 Bravo that has been cut and worked that you can spin and see how it handles. Just let me know.

Bryan
904-738-1988
 
merc106

merc106

Active Member
Joined
Jun 25, 2008
Messages
81
Points
8
Location
Gainesville
Thanks Bryan I'll give you a call. The boat has the skid plainer that is flush with the back of the boat. Not so sure about that thing! Wind shield is on for now. I'm shooting to run as fast as my xb03 setup is my goal. We will see.
 
merc106

merc106

Active Member
Joined
Jun 25, 2008
Messages
81
Points
8
Location
Gainesville
Todd, that cleaver style prop you told me about, how high do you think the engine would run with it? Would it lift the bow like a regular prop or nose down and just lift the complete boat?
 
You must log in or register to reply here.
Top