Quinte Fishing

Hello Members...thought I would pose this question to the Pros out there.

I am upgrading my Prop to a Stainless for my 150Merc 4S. Wondering what difference I might expect between a 4 blade and 3 blade stainless. I do have some very minor cavitation issues with the factory setup which will get addressed under warranty when I put it up for the season and my son recently kissed a rock backing out of a slip with the factory aluminum...very minor ding but always knew I was going to go with stainless.

I also see quite a difference in price between factory and after market.

Any advise would be appreciated.

Steve
From Muskoka

Boat Propeller Advantages/Disadvantages

Aluminum Boat Propellers:
Advantage- cost.
Disadvantage- blade flex and poor durability.
3 blade propeller vs. 4 blade aluminum propeller:
4 blade Advantage- better hole shot and increased stability.
4 blade Disadvantage- Top end speed.

Stainless Boat Propellers:
Advantage- overall performance, no blade flex, durability.
3 blade propeller vs. 4 blade stainless propeller:
3 blade Advantage- performance, good acceleration, best top end.
4 blade Advantage- best hole shot, increased stability and fuel economy.
5 blade stainless propeller:
Advantage- good hole shot.
Disadvantage- mid-range, top end and fuel economy.

_________________
Fred Fisher....

Fishy Fishy In The Bay, Bite This Line And Make My Day....

To add to Fred's points.

-each prop has different characteristics ; bow lift, stern lift, stability. Even between identical props of the same make/model.
-setup (engine height, setback, proper trim) needs to be considered along with prop choice. Some props need to be deeper (Fury), some need less (Trophy)
-be mindful that when testing the prop(s) in the spring, you will see different results when compared to the dog days of summer and/or with a full load. You may be a full pitch lower mid-summer.

If possible, try a few different props. See if your marina will let you try before you buy OR borrow from a buddy.

Kiss a rock with alm and most often good to go with new prop. Kiss a rock with stainless and often brake something else too 3 blades throw a rooster tail, 4 & 5 blades don't. We have always went with 2-3 different alm depending on what we are doing. pitch plays a huge role and watch your RPM's!
Grillzy

http://www.bbcboards.net/props/

_________________
Thanks to Pro Advantage

Guys/Gal...thanks for the input. As luck would have it I will have the opportunity to try a couple of different props/pitches. My new boat is a new setup for Lund... 18.75 Crossover with this motor package and I am hoping the prop change might solve the minor cavitation issue I have experienced from the getgo as well.

great analogy Fred.
yes Grillzy...been worned of that more than once, thankfully my son fessed up to it and learned his lesson. Confessed kissing a rock was more expensive than kissing his wife!

Thanks again...

Steve
From Muskoka

Interesting note...

Just picked up a couple of different Props to try and had taken my old one in. The finish on the Prop is completely of 2/3rds of all 3 blades which according to the tech guy that looked at it is a good indication confirming cavitation.

I did not know that as an indicating factor but guess it would make sense given the amount of flex in the aluminum prop.

Walleyewon,

I have an 18 foot Lund Pro-V with a HO 150 HP ETEC with a SS 3 blade Raker II. I believe it is a 21 inch pitch prop. One commenter talked about a 3-blade rooster tail. Well they are right in my case. I have one that is at least 5 feet high. It is best to have your rpm close to the recommended max rpm at full open throttle. I get close to 5600 rpm at WOT. I have never experience any cavitation issues either at high speed or turning. If I trim down I do like to slow down to make sharp turns because the steering is very tight at high speed and low trim. I do not have any trouble turning at high speed if I have the motor trim up high. In 4 ft waves and low gas in my fuel tanks the boat can be a little harder to control at full speed. I'm used to it but an old lady my roll the boat. For rough water I sometimes wish I had a four blade to give me increase stability. Thing is, the real rough water conditions are few and far between on the back lakes that I frequent most.

For most conditions you should look into a 3 blade High cupped prop from Mercury if you fish back lakes. If you spend most of your time on one of the Great Lakes look at a 4 or 5 blade prop. Whatever prop you pick, it should not cavitate excessively and should run as close to max recommended rpm at WOT.

Good Luck picking a prop. It can be a challenge to say the least. Some boaters never find the right prop.

BATMAN

Batman...what you say helps...as well as MattClap..."each Prop performs differently"!.
A Teck rep from Lund has been in touch with me and did confirm after further testing they are "future" recommending a 19 pitch ALM for my setup.

Probably didn't pay the attention I needed to with the sales guy when I ordered it. 40HP was my last motor and trim was hardly an issue.

They Rep was convincing SS over ALM and that is what I am trying this weekend (a 4 & 3 blade 19Pitch and 3 blade 21 Pitch). Wants me to monitor my RPM/speed while trimming up to cavitation. I explained that I could only achieve just above an 8th on the trim guage before cavitation at full throttle...should be half ther abouts?

150HP is the biggest motor I've had...it would appear my cavitation is more serious than originally thought.

Thanks for your help Guys...I will be sure and post my findings.

Well...settled on a 14x19P LaserII SS for my boat after testing a few different Props and having indepth conversation with a Lund Rep.

Turns out formal testing for the Lund Crossover was done after my purchase and Mercury Marine had made thier recommendations to Lund for the otimum set-up.

Interesting find...the Mercury Marine web-site has engine tests with various props on a variety of boats which was most helpful, this gives RPM, MPG, Top Speed and best fuel economy data...Just have to find you engine, click engine tests, scroll to find your boat.

Thanks for the feeback guys.

Steve