looking for a new prop

[ninjafied]

hey guys i have a 2015 bass tracker pro team 190 equipped with a 2015 mercury 4 stroke 90hp.
my current prop is aluminium 3 blade 19 pitch and allows me to top out at 48 mph very near the rpm redline. i'd like to switch to a stainless prop but not sure about the benefits of 3 vs 4 blades.

[Princeton_Man]

hey guys i have a 2015 bass tracker pro team 190 equipped with a 2015 mercury 4 stroke 90hp.
my current prop is aluminium 3 blade 19 pitch and allows me to top out at 48 mph very near the rpm redline. i'd like to switch to a stainless prop but not sure about the benefits of 3 vs 4 blades.

Typically, a four blade prop will give you a better hole shot, get you on plane quicker. Four blades also have more grip on the water for better control and handling in rough water and tight bends.  A three blade prop will generally give you the most speed. Not a lot more but usually 2 or 3 mph more.

Choosing the right pitch has a lot to do with your current numbers. Mostly what your wide open throttle RPMs with your current prop. If you choose a 4 blade, you'll want to drop 1" in pitch. It can be a little tougher finding the right prop when going from an aluminum prop to stainless steel because aluminum props flex some which changes their pitch a little. It's a big plus if you have a marine dealer or prop shop who sells props and will let you water test them first.


Most of all, knowing what other with your setup are using will help a lot.

[ninjafied]

hey thanks for the reply yes i am wondering what others with the the same or similar boats are running.
also i checked my prop and as it turns out i"m running a 21 pitch. i am also aware that adding an inch of prop will drop rpms by about 200 if i stay with a 3 blade aluminum prop.
so what are the differences in aluminum vs stainless and 3 vs 4 blade props

[Oldfart9999]

Take a look at the Mercury Spitfire prop, it's based on their Fury stainless prop but is an aluminum with high performance numbers at a price lower than a stainless.
Rodney

[coldfront]

hey guys i have a 2015 bass tracker pro team 190 equipped with a 2015 mercury 4 stroke 90hp.
my current prop is aluminium 3 blade 19 pitch and allows me to top out at 48 mph very near the rpm redline. i'd like to switch to a stainless prop but not sure about the benefits of 3 vs 4 blades.

I run a 75 Opti.  went from a 3-blade aluminum to a 4-blade aluminum.  current prop is a mercury spitfire 4-blade 13x17.

merc website has a great 'prop-selector' tool. 
https://www.mercurymarine.com/en/us/propellers/selector/#!/step-one

way better 'bite' on turns, sharper turns.  no blow-outs.  now, with a boat that I cruise in at 30mph (4900 rpms) I don't notice any change, loss in speed.  My preference will always lean to 4-blade.

know aluminum might not be as stiff as stainless, but it's a heck of a lot cheaper and guessing if you're running less than 200 hp you're not necesarily in a lot of boat races?

although, if I could get 2-3 more mph top end out of my outboard, not so sure I wouldn't be chasing it!

[simek3ru]

I run a 75 Opti.  went from a 3-blade aluminum to a 4-blade aluminum.  current prop is a mercury spitfire 4-blade 13x17.

Did you change pitch when you made the change?  I have a 14 pitch WOT at 5400 RPM, bought a 13 pitch 4-blade last year and WOT was at 6000 RPM.  I always read to go down an inch when switching from 3 to 4, but in my case I'm thinking of staying the same pitch and trying again, that's why I'm curious as to what you did

[coldfront]

Did you change pitch when you made the change?  I have a 14 pitch WOT at 5400 RPM, bought a 13 pitch 4-blade last year and WOT was at 6000 RPM.  I always read to go down an inch when switching from 3 to 4, but in my case I'm thinking of staying the same pitch and trying again, that's why I'm curious as to what you did

I've followed operators manual to stay at same WOT rpm.  for my 75 opti that should be 5500-5550
if I run it higher, figure I up my odds of blowing it up?

for this situation, pitch stayed same.  think original was 13.5x17.  the 4-blade option closest was/.is 13x17

WOT RPM's are same.  speed is pretty much same, near as I can tell via GPS.


Mostly, I run my outboard at 4900-4950 rpm's when moving spot to spot.  figure that's better than maxing it.  plus, it gets me around at roughly 30 mph.

would I love to go faster?  you really don't even need to ask.

eventually, I'll get my 'last' boat and it'll have an outboard that will allow me to push past 60mph.
still, I expect MOST of my cruising will still be around 45-50mph.  raindrops and bugs hurt even at 30;.