CcScorpion311

I have a 1996 Fountain 31 open. Has twin 96 Merc 250 xs with Bravo 22p @5800rpm it hits 61. From what I’ve read this boat should be faster.
Anyone with the same setup or can offer suggestions on props?

HTJ

Are the motors all the way up?

CcScorpion311

one hole from the top.

nautiboyz

Propbender or propgods would be able to hep you. What is the max rpm rating on those motors? Do you have alot of slippage throughout your rpm range

CcScorpion311

They hook up with no slip. I believe max rpm is 6200 It has the Vrod HD 1.75 lowers

sundancekid

One hole from the top as in one more to go up or only one more to go down? Props are definitely light, you’re rev limiting at 5800 with those motors. Bravo 25 FS would be my choice for every day with that setup. Mount them in the middle hole at least, if not higher depending on how heavy you run.

CcScorpion311

One hole to go up only. I always run a light load so I want the fastest setup.

Apexwarrior

61 mph with 250's sounds pretty close to me. I think you need more hp if you want to go faster.

One truth about boating is that everyone lies about how fast their boat goes..

BiloxiGuy

I owned that exact setup. It is well documented that the 31 Fountain is a 62 mph boat with 225 Opti's turning 22 Bravos.

The 250XS’s were putting out around 275 hp.

With 250XS's, you basically have two choices: 24 Bravos (for top speed running light) or 23 Rev 4's which is the best overall prop for fishing load etc.

The motors should be mounted in the middle holes.

I ran 23 Rev 4's, and it was propped perfect for me. Here were my numbers running with medium load:

4000 rpms = 45 mph (2.25 mpg)
4500 rpms = 52 mph
5000 rpms = 57 mph
5800 rpms = 65 mph


With that being said, these newer technology props (Mercury Eco's, etc) were not out at the time that I owned the Fountain, so I have no idea if any of the newer props would now be the way to go.


Good luck, that was a fun boat!

CcScorpion311

Thanks! I’m going to call F&J Monday and see if they have a loaner set of 24’s

westco

You say 96 250XS. Don’t believe the 250XS was made in 96 so do you have 250EFI or was 96 a typo? A buddy had a 31 with Merc 250s and it was a 65 mph boat, pretty sure he was running 24 Bravos

sundancekid

I’d look for a set of 26 Bravo FS then for Max speed and leave the engines where they are.

CcScorpion311

Sorry, 2005 Merc 250 xs

BiloxiGuy

Mine were 2004’s on a 1997 hull, just for reference.

CcScorpion311

So just go back after running Bravo 1 24P lost 3mph topping out at 59mph @ 6100rpm’s. I was hoping after all the research that the 24p would be the right ones. Now what?

HTJ

You went up 2" on pitch, gained 300 RPM but lost speed...something is not computing here.

aswaff400

i spent a lot of time finding the limits of my old 31 fountain, prop testing, engine height, lower units rotation in/out, steering toe in/out, lower unit size 4.8 vs 5.44hd.

with 1.75 fleetmaster (4.80 lowers):
25p mirage plus mounted on second from top holes: 64.5 mph @ 5300 rpm
25p mirage plus on bottom holes 68.5 mph @ 5700 rpm
26p bravo 1 fs on bottom holes, 72 mph @ 5850 rpm
26p bravo 1 fs on jackplate, 72.7 mph @ 5950
28p bravo 1 fs on jackplate, 73.8 mph @5750

with verado 5.44HD 1.75 lowers:
23p bravo 1 fs 61mph @ 6000/rev limiter
26p bravo 1 fs, 67mph @ 5850 rpm

CcScorpion311

[QUOTE=aswaff400;13922086]i spent a lot of time finding the limits of my old 31 fountain, prop testing, engine height, lower units rotation in/out, steering toe in/out, lower unit size 4.8 vs 5.44hd.

with 1.75 fleetmaster (4.80 lowers):
25p mirage plus mounted on second from top holes: 64.5 mph @ 5300 rpm
25p mirage plus on bottom holes 68.5 mph @ 5700 rpm
26p bravo 1 fs on bottom holes, 72 mph @ 5850 rpm
26p bravo 1 fs on jackplate, 72.7 mph @ 5950
28p bravo 1 fs on jackplate, 73.8 mph @5750

with verado 5.44HD 1.75 lowers:
23p bravo 1 fs 61mph @ 6000/rev limiter
26p bravo 1 fs, 67mph @ 5850 rpm

CcScorpion311

[QUOTE=CcScorpion311;13922124][QUOTE=aswaff400;13922086]i spent a lot of time finding the limits of my old 31 fountain, prop testing, engine height, lower units rotation in/out, steering toe in/out, lower unit size 4.8 vs 5.44hd.

with 1.75 fleetmaster (4.80 lowers):
25p mirage plus mounted on second from top holes: 64.5 mph @ 5300 rpm
25p mirage plus on bottom holes 68.5 mph @ 5700 rpm
26p bravo 1 fs on bottom holes, 72 mph @ 5850 rpm
26p bravo 1 fs on jackplate, 72.7 mph @ 5950
28p bravo 1 fs on jackplate, 73.8 mph @5750

with verado 5.44HD 1.75 lowers:
23p bravo 1 fs 61mph @ 6000/rev limiter
26p bravo 1 fs, 67mph @ 5850 rpm

Great info! I’m going to try and get set of 26FS tomorrow. On the FS do I leave out all the vent plugs? Motors have one more hole to go up. If I raise them how much mph does that really help?
Thank you!

westco

[QUOTE=CcScorpion311;13922143][QUOTE=CcScorpion311;13922124]saw on the post above, same prop, one hole up=4 mph faster