buying replacement/spare propeller

dsokodrum

Hi!
I have a 1994 festiva 2002 with a 3.0 l merc.
What should I know about replacement and/or having a spare prop? Would like quicker plane response. Don't know much about pitch etc...
any advice appreciated.

Black_Diamond

First, what outdrive do you have? If a BIII don't bother with a spare, $$$ and damage if you strike something. In general you want a prop pitch that will let the engine rpm at wot hit the max rated rpm, anything more or less will have the engine running out of its best power range.

jhuis73

Wot- wide open throttle yours should be 4400-4800

212rowboat

Wide open throttle (wot)... If you're running too shallow a pitch (lower number), you'll be able to over rev the engine.. not good.. you want to turn the engine (and therefore screw) within the 4400-4800 rpm window.. too steep a pitch (higher number) will not allow the engine to achieve the rpm, because it would be too loaded, it will consume too much fuel, and stress parts and pieces almost as bad as over revving does.

BoatAway

drewactual said:

Wide open throttle (wot)...

Michael T

Before you replace that tach remove your dash cover plate and see if the wires are on tight. Tachs are notoriously fickle and a loose wire can cause them to stop or act stupid. Cheaper to look first. P.S. I have never heard of a 25" pitch on a 3 litre rig unless it was a trawler. Even a 23" pitch seems tall. Of course I'd have to know your gear ratio to be sure. I'm thinking 17'" pitch for hole shot and 19" for normal use? MT

dsokodrum

How do I check which type? And thanks for the fast response, though I can't tell you what out-drive till Friday. We bought the boat used with no literature. actually it was beat up! A pole barn crushed it during storage. though you cannot tell that there was three holes in the port side can you?

mvn

If it's a 3.0L, it's probably an Alpha 1. We would need your stern drive gear ratio and the maximum WOT rpm from the sticker on your engine, if possible, in order to make a recommendation. Can you get any part numbers from your existing prop?

Mark

brianluck

the general rule of thumb is determine what pitch you have, what your wot rpm is. then make your changes based on what you want. dropping pitch will add rpms. increasing pitch will lower rpms. then you have 3 blade vs 4 blade. aluminum vs stainless  http://bblades.com/picking-the-right-propeller/

vquad

I would do a google search in your area for "boat prop repair" or "prop services"

the owner/tech should be able to steer you in the correct direction and more than likely have a rebuilt prop for you to purchase as well at a discounted rate over the price for a new one

my local guy is mike with "halls prop service" at 407-568-5506 if you wanna give him a call...

hes got thousands of used props in stock

dsokodrum

Sorry guys, hate to sound dumb but, what is "wot" ?
To Black Diamond; I have an Alpha one.
As far as numbers off from the prop, it may well be the original, pretty worn and can't visibly see numbers.
I'll have to go back to look at engine for WOT rpm.
You've all been very quick to help, Thank you!

Black_Diamond

Black_Diamond

dsokodrum

Yes, 4400- 4800 =WOT.
as far as numbers on  the prop. the last few looked like... 17'P
I'm guessing that it is a 17 degree pitch? 3 blades and it's not  stainless.

A lower pitch # would get me out of the hole faster, so to speak, but slower top end speed.
While a higher pitch would be a slower take off but a faster top end speed? I believe that is what I'm reading into on most sites. Just the same, I will probably just match it.Thanks for all your help!

Black_Diamond

Pitch is in inches. So in a perfect sense a 17P will move forward 17" in one revolution.

KYSEAN

I have a brand new 16P SS you can have for a steal if it'll work for you.

dsokodrum

The numbers on my prop is....48 78118 A40 17P.
KYSEAN. If everything fits.make me an offer.

KYSEAN

If you need to gain 150-200 rpm, the one I have would be perfect. It's a 15 spline 16P SS Enertia. Brand new but with the added benefit of being balanced and tuned. Never been installed or seen water. In the box with documentation. 350.00 shipped. If you could use it call me 270-320-1862

dsokodrum

thanks to some searching, I just got the speedometer working again. Darn pitot tube! Now the tach stopped. Probably replace it first so I know my rpm's.

dsokodrum

I 'm sure I need to see a Mercury dealer.
I do not believe my current prop,(17.0 pitch) is original, or what it should be. According to Mercury site on prop choice;If I choose by boat length, I need a 25.0 pitch.
           by  boat weight (7 passengers and 30 gallons of fuel) 23.0 pitch. WOW!