What back-up/Spare Prop?

[sigepmock]

Posted this in Outdrive Tech but thought I'd try here too...
What Back-up/Spare Prop?
Ok I just picked up our new 21' Ultra Stealth with a 6.2L/Bravo 1 and it came with a five blade 21P. My question is what prop should I get as my back-up/spare prop?
My last boat was a jet so I am in need of some prop schooling. Am I correct to think that this five blade 21P should get me out of the hole good and tow skiers well but lack a little on the top end? Should I get a 4 or 3 blade back-up so I can switch between the two....one for towing skiers/wakeboarders and one for cruising higher speeds?
Any help, advice, opinions, or links to prop 101 would be appreciated.
Thanks,
Chris "Don't know much about prop selection" Mock

[Essex502]

Prop selection is a trial and error proposition. Some hulls like 4 blade props and some like 3 blade props. I have never used a 5 blade prop and if that works for you on some level then stay with it. You might want to find a shop that will let you demo a prop or props until you find the one that works best for your hull and power.
Our boat came with a 23P 3 blade Mirage Plus and I've run 24P 4 blade Bravo 1 prop as well as several 25P 3 blade Mirage Plus props. Turns out the best low end and mid range prop is the 4 blade and the best handling and top end is the 3 blade "lab'd" 25P. Your results may differ.
If I were you I'd ask your builder's advice on what to get as an alternate to the one you received. That would be a starting point for the testing.

[sigepmock]

Thanks
Chris

[THOR]

My Dad has that exact boat but with a 350 Mag and he runs a high five 21P too. It works great, but he sometimes runs out of prop. I would honestly get another 5 blade, but use a 22P. That would be great for cruising a tad faster. I see them on ebay all the time. You can save about $200. They retail at $500 for a stock Bravo 5 blade.

[RiverDave]

If your looking for a top end prop I'd bet that a 4 blade 22 Bravo I is going to be a pretty good one.. you might even get away with a 3 blade 23 pitch if it's labbed?
Friend of mine runs a 21 Ultra with a 350 / Bravo I and he runs a 3 blade on his, runs pretty good.
RD

[mirvin]

Hey Dave, I'm running a 3 blade 21P on my 5.7 (350)......Do you think I should try a 22 or 23? How about 4 or 5 blade?
I'm spinning the 21 up around 5600 to 5700 rpm.
Thanks,
mirvin

[sigepmock]

Thanks for the reply's guys, after spending all day on line reading about props I think I'm starting to understand them a little. I'm gonna start by actually driving the boat this weekend and see how it does and RPM's it will turn and then go from there. So far the consensus seems like I'm probably somewhere between a four blade 23P or 22P. We'll see how the 5 blade 21P does this weekend.
Thanks again,
Chris

[CBLavey]

Wait...until your engine is past the break-in period. I have that same engine in my 21 Lavey and you should be able to turn 5200RPM on the high side of the operating range. The 21" High Five is a great hole shot prop but soft in the mid-range and top end.
I'm spinning a 23" Bravo 1 four blade and have no problem pulling up a slalom skier with a boat full of gear and people. You will lose some hole-shot with the four blade but the mid range and top end are much better.