Evinrude 60hp - 3 Blade vs 4 Blade Prop Pitch

[Demonical]

My boat is a 1991 Lund Fury 16', and my engine is the 3 cylinder Evinrude VRO 60hp.

I decided to buy a new stainless prop and went from the original 3 blade aluminum to a 4 blade.

The prop I have on the engine is a SS Turning Point Express 4 blade prop: 3143 1730, 13.25" x 17 (pitch).

With that prop vs my old aluminum, my RPMs have dropped. I'm planed out running about 4400rpm, so a pretty drastic drop. With the old 3 blade aluminum, I used to get around 5300rpm max, but would usually trim it to run about 5100-5200, where the boat rode nice.
But I (stupidly) didn't keep the old prop so I do not know the specs of that original prop.

Well now I'm thinking I should go back to a 3 blade, I still want the stainless prop.

I've got a spec sheet here for an Evinrude SSP #763951, 13.25" 17 pitch prop.

Evinrude Johnson SSP Stainless Steel Boat Propeller #763951 for Evinrude 60 HP Outboard 1986 - 2001 3-Cyl., Pleasure - iboats.com

Fast shipping and huge savings on Evinrude Johnson SSP Stainless Steel Boat Propeller #763951 for Evinrude 60 HP Outboard 1986 - 2001 3-Cyl., Pleasure

boatpropellers.iboats.com

So my stupid question is, if I put this 3 blade on my engine is it going to be the answer to return my rpm back to 'normal'?

 

[jimmbo]

Maybe, maybe not.

 

[jimmbo]

Without knowing what prop was on there prior, it is a crapshoot was to whether this next purchase will be any better. However, a 17" is a pretty fair starting point.
You want the Rpms at WOT to be in the upper end of the WOT Rpm range for that engine, which I am going to guess is 4500-5500. Why did you decide to go with SS?

 

[racerone]

If you are only getting 4400 RPM with a 17" pitch there is something wrong with your motor !!-----You need to do some testing / inspection.-----Post compression numbers ( #2 ) is often low.-----Does tell tale hose come off the top of the block or off the side on exhaust cover?

 

[airshot]

How did you decide on the pitch of this 4 blade ??

 

[jimmbo]

If the 3 blade was a 17, the extra Blade, could account for a lot of the Drop.

 

[jlh3rd]

"I decided to buy a new stainless prop and went from the original 3 blade aluminum to a 4 blade."


# of blades, diameter of prop, pitch of prop, cupped prop or not, all affect rpm. Not just # of blades.

 

[Demonical]

How did you decide on the pitch of this 4 blade ??

2 years ago, before i rebuilt my boat carbs, I had to get the carbs cleaned, didn't have time to do it myself, so took it to a shop for that service.
While they had it I asked them for a new prop, my old aluminum was getting on in age, and I wanted to go stainless.
The 4 blade SS was spec'd by the shop and I said okay on it. So basically they picked the prop and I didn't know any better.
When I got the boat back home I did have the old alum prop, but either it got thrown out, which woulda been the wife telling me to toss it, and then me going along with that idea. Which was a dumb idea frankly.

 

[airshot]

You didn't question this poor performance all this time ?? That would be a dealer, I never went back to except for a refund !!

 

[racerone]

I would say at 4400 RPM max that there is something wrong with the motor.----This is not a 3 verses 4 blades issue.-----Do some trouble shooting on the motor !!

 

[MRS]

2 years ago, before i rebuilt my boat carbs, I had to get the carbs cleaned, didn't have time to do it myself, so took it to a shop for that service.
While they had it I asked them for a new prop, my old aluminum was getting on in age, and I wanted to go stainless.
The 4 blade SS was spec'd by the shop and I said okay on it. So basically they picked the prop and I didn't know any better.
When I got the boat back home I did have the old alum prop, but either it got thrown out, which woulda been the wife telling me to toss it, and then me going along with that idea. Which was a dumb idea frankly.

Why would you not keep it for a spare prop you do need to keep a spare on board. So get a three blade and see how that works.

 

[Demonical]

You didn't question this poor performance all this time ?? That would be a dealer, I never went back to except for a refund !!

My engine is a 1991 and I bet it has fewer hours on it then the average 2021 model engine.
You have to understand that, where I live in Whitecourt Alberta, there's no lakes around here unless I drive an hour to Fox Creek, or 2 hours to Lesser Slave Lake.
And for the record, I haven't been to Iosegun L or Smoke L (Fox Creek area lakes) since about 1995. And I get up to Lesser Slave L like once a year, for a 3 to 4 day fishing trip.
Which consists of me starting the engine, getting on plane and running 600 yards down the lake to the 'Cutbank' (from Hilliard's Bay campground).
I anchor. Still fish.
After done fishing I run back to the boat launch and trailer the boat.

And that has always been my M.O. with this boat and engine. Run from the launch anywhere from 400 to 600 yards to hit the walleye fishing spots along Slave Lake, at Spruce Point or at Hilliard's Bay. Anchor, still fish, return to camp for beers and fish fries.

My engine is never run for anything else. I don't 'pleasure' ride. I don't water ski.

So to repeat:

After the dealer worked on my engine it ran like ****. I think all they did was spray some Sea Foam or something like that into the carbs.
So it ran so crappy, after their 'service', that you couldn't make any serious evaluation on it. But the new prop was on it then.

And you are correct Airshot, I will never go back to that shop again.

So I pulled my carbs and cleaned them. Last year.
But I only had the boat on the water ONE TIME, in 2022.
The on-water performance this year is totally due to the wrong prop, the 4 blade is too much for my 60hp.

The engine actually ran perfectly. No issues other than clearly the 4 blade is too much.

 

[jimmbo]

What about McCloud Lake between Whitecourt and Swan Hills? You could also head towards Barhead, where Lac la none, is, and Lac St. Anne a few miles further on.

 

[Demonical]

What about McCloud Lake between Whitecourt and Swan Hills? You could also head towards Barhead, where Lac la none, is, and Lac St. Anne a few miles further on.

McLeod Lake/Carson Lake has Rainbow Trout in it, which I don't care to fish for. And it's a small lake, LOW SPEED lake.
I've been to Lac La Nonne like 30 years ago?
Lac Ste. Anne about 25 years ago I guess?

The only lake worth going to, to fish for Walleye is Lesser Slave Lake.

The best Walleye fishing locally is actually the McLeod River. The wife and I go out on it in 12' kayaks. You cannot take my Lund down that shallow river.

The other best fishing is in some of the small off road lakes, for Brook Trout. The stuff you access with ATV/Snowmobile. But I don't do that either.

 

[jlh3rd]

My engine is a 1991 and I bet it has fewer hours on it then the average 2021 model engine.
You have to understand that, where I live in Whitecourt Alberta, there's no lakes around here unless I drive an hour to Fox Creek, or 2 hours to Lesser Slave Lake.
And for the record, I haven't been to Iosegun L or Smoke L (Fox Creek area lakes) since about 1995. And I get up to Lesser Slave L like once a year, for a 3 to 4 day fishing trip.
Which consists of me starting the engine, getting on plane and running 600 yards down the lake to the 'Cutbank' (from Hilliard's Bay campground).
I anchor. Still fish.
After done fishing I run back to the boat launch and trailer the boat.

And that has always been my M.O. with this boat and engine. Run from the launch anywhere from 400 to 600 yards to hit the walleye fishing spots along Slave Lake, at Spruce Point or at Hilliard's Bay. Anchor, still fish, return to camp for beers and fish fries.

My engine is never run for anything else. I don't 'pleasure' ride. I don't water ski.

So to repeat:

After the dealer worked on my engine it ran like ****. I think all they did was spray some Sea Foam or something like that into the carbs.
So it ran so crappy, after their 'service', that you couldn't make any serious evaluation on it. But the new prop was on it then.

And you are correct Airshot, I will never go back to that shop again.

So I pulled my carbs and cleaned them. Last year.
But I only had the boat on the water ONE TIME, in 2022.
The on-water performance this year is totally due to the wrong prop, the 4 blade is too much for my 60hp.

The engine actually ran perfectly. No issues other than clearly the 4 blade is too much.

a 60 hp motor on a 16' boat needs a different prop than the same motor on a 24' boat...I know for a fact.
A prop ad that says it will fit a motor doesn't mean that's the prop you need for that motor on your boat. But that's the message I got from you posting that ad......
I believe you know your motor....
because you don't know what the original prop size was, you are back to square one for propping your boat.....
....I repeat, it's not just pitch that changes rpm's....

The pic is a 4 blade, 13.8x11 I put on my 60 hp motor pushing my 24' pontoon. This is just an example of what it took for that 60 to work on my 24' pontoon.......I am not saying buy this prop...it's just to illustrate....

 

[racerone]

If 4400 RPM is maximum with 17" pitch , there is something wrong with the motor.----Find a shop with a dynamometer or test prop and have power output checked !!

 

[jimmbo]

McLeod Lake/Carson Lake has Rainbow Trout in it, which I don't care to fish for. And it's a small lake, LOW SPEED lake.
I've been to Lac La Nonne like 30 years ago?
Lac Ste. Anne about 25 years ago I guess?

The only lake worth going to, to fish for Walleye is Lesser Slave Lake.

The best Walleye fishing locally is actually the McLeod River. The wife and I go out on it in 12' kayaks. You cannot take my Lund down that shallow river.

The other best fishing is in some of the small off road lakes, for Brook Trout. The stuff you access with ATV/Snowmobile. But I don't do that either.

Calling Lake was well known for Walleye. Spent my Teenage Summers at that lake.

 

[airshot]

Unfortunately motors are designed to be used, the more they are run, the fewer issues you will have. And the opposite is also true, the more they sit idle the more issues you will likely have !! If nothing else, get a pair of water muffs and run the motor in your driveway once or twice a month. Get a small fuel tank so you can run fresh fuel thru it often... My boat gets used, but not as much as I would like, if a couple weeks or more go by without use, I hook up the hose and let it run for 15-20 minutes and keep things "lubed up" as my Dad used to say !! When winter storage time comes around, I do the proper steps for storage, and over 60 years of boat ownership, I have had very few issues...knock on wood !!