Recommendations for prop pitch for 1994 Johnson 40hp 2stroke outboard

[Seafury]

So I found one of the very few rocks on the river I have been fishing lately.

 

My stainless prop is trash now, curled off a half inch of the tip of one blade, and bent another blade, still ran fine and got us back to the ramp with no noticeable issues.

Also looks like my shaft is slightly bent now, but it may have been that way before, I never really looked at that.

 

The prop on the boat has zero markings that I can see with it still mounted.

Guy I bought it from doesn't know what the pitch is/was.

 

Boat currently does 29-33mph with me and/or 1 person on board.

16ft aluminum front stick steer Lower 162 1994 model hull weighs about 700lbs give or take.

Original outboard motor.

Gets up on plane fine more or less from my limited experience.

With 2nd large passenger in the rear, it was slower to get up on plane but then had better top end due to better balance of weight I think.

 

It's tough to find info on this topic or this specific older motor.

I already know I'm buying another stainless (I need the durability, I have already bumped into many stumps/trees at low/idle speeds with no issues)

Can anyone tell me what pitch prop I should get to take the guess work out of this for me?

 

Thanks for your time.

 

[gim]

Unfortunately there is not a good answer on props.  It's a fine line between blade pitch and RPM.  I've gone through this process myself and my experience did not yield a good result, even though the "specialist" at the prop shop was hell bent I'd see an improvement.

 

The only real way to get what you're looking for is to try a specific prop and see how it goes.  It may take multiple attempts to get what you're looking for.

[airshot]

Remove the prop and you will probably find the numbers on the hub. The reason your damage is so severe is due to the SS prop, while alum props break more easy, they spare the shaft and lower gear case.

As far as the proper pitch, you need the max rpm at wot on your previous prop, then adjust pitch according to what your rpm was in relation to max rpm your motor is rated for.  If you don't have that, then it is all a guess....before you do anything, the lower unit needs rebuilt or you won't get very far with a bent shaft.

[A-Jay]

Buy aluminum, several in fact.

Compared to the $ of SS, they are practically disposable.   Seems you need less speed and more accurate helmsmanship.  Or buy a jetdrive lower unit.

A-Jay

[WRB]

13P” 3 blade is normal.

Tom

[Woody B]

1 hour ago, WRB said:

13P” 3 blade is normal.

Tom

 

Yep,  a co worker has a Tracker Panfish model, stick steer with a 40 Merc.  He runs a 13" pitch.   If you're going stainless go down to a 12" pitch.  You current prop should be marked somewhere.   

 

As far a top speed, handling ect.  It's my experience that proper balance and weight distribution will gain more performance than a "magic" prop.   I have a SS prop, with some extra cupping.  This get's my boat "up" enough for a super smooth ride and great handling.  My factory aluminum prop was 1/2 mph faster.   

[Will Ketchum]

It's interesting that prop pitch is a topic because I recently bought a fan blade for a heater blower motor in my basement and pitch was one of the criteria.

 

I took the old fan blade and measured one blade's width. Then, with the fan laying on a flat surface, I measured one side of the blade's height from the surface. I then had two sides of a right triangle, the width and the height, and used trigonometry to figure the two other angles, one of which was the pitch in degrees.

[Seafury]

4 hours ago, gimruis said:

Unfortunately there is not a good answer on props.  It's a fine line between blade pitch and RPM.  I've gone through this process myself and my experience did not yield a good result, even though the "specialist" at the prop shop was hell bent I'd see an improvement.

 

The only real way to get what you're looking for is to try a specific prop and see how it goes.  It may take multiple attempts to get what you're looking for.

I was affraid of this.

I don't have money to buy multiple props right now and do trial and error.

I figured this old motor and boat (with several identical models across different brands) would be fairly well known already as to what I need.

 

Thanks!

[Seafury]

2 hours ago, airshot said:

Remove the prop and you will probably find the numbers on the hub. The reason your damage is so severe is due to the SS prop, while alum props break more easy, they spare the shaft and lower gear case.

As far as the proper pitch, you need the max rpm at wot on your previous prop, then adjust pitch according to what your rpm was in relation to max rpm your motor is rated for.  If you don't have that, then it is all a guess....before you do anything, the lower unit needs rebuilt or you won't get very far with a bent shaft.

Basically I'm not trying to get max anything, right now.

I just want to replace the prop with the same setup in whatever brand, it was working fine for my needs and was safe for the outboard.

 

Boat has no console or gauges.

I'm sure I could buy and install an RPM gauge for testing, but seems a waste of time for my needs.

 

Yea I figured the old prop might have some markings inside where I can't see it.

I did not remove it yet, probably should have done that today before I put the boat away /sigh.

I'll try to do it later this week as it's too late now with rain and storms here and daylight fading fast.

 

As for the lower unit yes, the prop shaft has a very slight wobble to it, but it may have already been like that for all I know. The boat still ran fine even after the tip of 2 blades were damaged yesterday.

No noticeable performance, or sound changes.

I really only nicked the rock and it was unexpected as I was in what I thought was and should have been, a safe spot when it happened.

 

I can't in good conscience run an aluminum prop where I am boating here in SC low country.

It's stumps and trees galore in tidal, sometimes very shallow water, outside of when I go to lake Moultrie.

I have bumped stumps at idle almost a dozen times already with no issues with the stainless.

My understanding is a standard aluminum prop will be toast the first time that happens.

When I finally move back to VA, or Mid-upper NC next year I will be out of stump country and back into mostly rocky rivers. Aluminum may make better financial sense at that time as I will be more likely to hit more rocks unless I am VERY careful.

For now down here I require the strength or stainless.

This rock event was extremely unlucky and should not occur again as there are basically no rocks around here at all.

This happened on a section of the Coosawhatchie "River" within 10 yards of I95 and a bridge over the river where they put rocks all along the shoreline I guess for erosion control.

Aside from this spot I have seen no other rocks anywhere around here when out boating, just a ton of stumps and trees.

 

I REALLY don't want to rebuild the lower unit right now, I'm trying to be ready to get back on the water next weekend, while working 8-5 M-F and it's dark when work ends and no garage so I have to use my lunch breaks to try and get this resolved before next Sat.

Trying to get all the fishing in I can before it gets too cold here (if that ever actually happens, I'm told it will, while it was 75 yesterday and 72/rain today lol)

Due to traveling for Christmas-New Years starting Dec20th, I won't have another chance to take the boat out again until Jan 6th so next weekend is my last shot for a few weeks.

[Seafury]

4 hours ago, A-Jay said:

Buy aluminum, several in fact.

Compared to the $ of SS, they are practically disposable.   Seems you need less speed and more accurate helmsmanship.  Or buy a jetdrive lower unit.

A-Jay

As I explained in some of my other replies, aluminum is not an option where I am boating here in the SC tidal low country due to the huge number of stumps and trees in the "fresh" water I fish in.

 

The rock was an extremely rare event and there are virtually no other rocks where I have been boating except this one place and I won't make that mistake again!

 

It also was not really captain error as I was several feet off the rocky shore in what "should" have been safe water 4-5ft deep, and I was trimmed up a little, and at idle speed, executing a U turn in about a 15 yard wide channel in high current.

It's a very odd place I was at and I got close to look at how the water was moving into this huge lagoon off the main river body though this narrow channel.

When we first got there mid-day the tide was just starting to come in.

Water was pushing inland, but this lagoon narrow channel access actually was higher than the river at the low tide, so water was draining OUT of the lagoon into the river that was flowing inland the other direction.

It exposed rocks and riffles in this narrow channel access at low tide and was wild looking as the 2 opposing water directions collided.

 

When I hit the rock was 2-3 hours later otw out to the ramp and the tide was now up about 2.5ft and starting to flow back into the lagoon, but I got to close and the high current started to pull us into the riffle area so I tried to turn around, and found this gd rock where it shouldn't have been lol.

This was the first time I was on this river at low tide.

It was wild seeing all the stumps and trees I drove over at 20+mph every time I went here previously during high tide.

I learned I need to be WAY more careful around here, and pay VERY close attention to the tide situations and water depth.

 

I am going to start looking into whether this outboard can be converted to a jet drive for when I move back north to rocky river country. I know nothing about jet drives other than they are slower than prop drive but safer to use around rocks and in shallow water.

 

If this motor can't be converted, I will have to look into buying an old used jet drive that will be compatible with the rigging already on my boat but I really don't want to deal with all that and really hope I can just convert the lower unit of this one which should be much simpler. (I hope)

 

 

Thanks!

 

[WRB]

The SST prop is repairable by a good pro shop. Another option is most pro shops have used repaired props for sale at a reasonable price.

Tom

[Seafury]

3 hours ago, WRB said:

13P” 3 blade is normal.

Tom

This is the information I was looking for, thank you!

So, your saying a 13 pitch, correct?

 

I'm seeing options from 11-17 pitch.

 

You reckon that applies for a stainless prop as well?

 

When looking up stainless props I am also seeing a hub dimension listed, and even the 13 pitch shows several options for hub sizes.

11 1/8th inch

12 1/2 inch

 

Also, some say "pressed hub" some say XHS-211, or RBX-111

More things to learn.....

 

Crazy how complicated it is just to replace a prop.

 

I am also seeing something about hub kits?

What's that about?

 

I'm also gonna check youtube for how-to's on prop replacement to get some education tonight.

2 hours ago, Woody B said:

 

Yep,  a co worker has a Tracker Panfish model, stick steer with a 40 Merc.  He runs a 13" pitch.   If you're going stainless go down to a 12" pitch.  You current prop should be marked somewhere.   

 

As far a top speed, handling ect.  It's my experience that proper balance and weight distribution will gain more performance than a "magic" prop.   I have a SS prop, with some extra cupping.  This get's my boat "up" enough for a super smooth ride and great handling.  My factory aluminum prop was 1/2 mph faster.   

Awesome this is exactly what I was looking for.

The tracker panfish is tracker version of the same boat as my Lowe, they are almost identical and have same size outboards.

so 13 pitch is stock prop size, why should I do 12 for SS?

 

Also what about the diameter options I am seeing?

11 1/8th for 13P

11 3/8th for 12P

 

Yea I figured the weight distribution change from having my first passenger was going to affect things and it did. Until yesterday I had only gone out alone and my big ass 255lbs driving in the front of this boat makes it light in the ass I think lol.

 

Not worried about maxing out speed or anything, just want what I had that worked fine and did 28-33 mph depending on wind and current direction.

 

Thanks!

2 hours ago, Will Ketchum said:

It's interesting that prop pitch is a topic because I recently bought a fan blade for a heater blower motor in my basement and pitch was one of the criteria.

 

I took the old fan blade and measured one blade's width. Then, with the fan laying on a flat surface, I measured one side of the blade's height from the surface. I then had two sides of a right triangle, the width and the height, and used trigonometry to figure the two other angles, one of which was the pitch in degrees.

For sure, fan blades for any application are a pita to figure out imho.

 

I also suck at math and trig is certainly a foreign language to me so no way I'm going near that lol.

[livin2fish]

I have a 40 hp Yamaha with probably a little heaver aluminum boat than you and I have the best luck with a 10 and a quarter inch prop with 15 pitch.  I have a 12 pitch, which creates too many rpm's, and a 17 pitch which will barely get me on plane with just me in the boat plus full 20 gallons of gas and water in the live well.

[Seafury]

14 minutes ago, WRB said:

The SST prop is repairable by a good pro shop. Another option is most pro shops have used repaired props for sale at a reasonable price.

Tom

Thanks for this information!

 

I will also look into this option.

 

Pics coming to thread soon as prop damage!

[Woody B]

7 minutes ago, Seafury said:

so 13 pitch is stock prop size, why should I do 12 for SS?

Aluminum props flex making what I consider the "effective pitch" different than the actually number.   FWIW the pitch number on a prop is the number of inches it moves per revolution.   

One variable is the gear ratio of the lower unit.   I don't know what ratio your engine is our how it compares to my friends Merc.   For livin2fish to be able to turn a 15 inch prop with a 40 horse his Yamaha gear ratio must be lower than my Mercury.  

 

If you're happy with your original prop I'd recommend trying to find a local prop shop to repair it.   

 

[Seafury]

23 minutes ago, livin2fish said:

I have a 40 hp Yamaha with probably a little heaver aluminum boat than you and I have the best luck with a 10 and a quarter inch prop with 15 pitch.  I have a 12 pitch, which creates too many rpm's, and a 17 pitch which will barely get me on plane with just me in the boat plus full 20 gallons of gas and water in the live well.

Thanks for sharing good info!

 

Yea I don't use my live well (no need for it currently) and I need to get the pumps working to even use it.

 

My boat is currently only carrying one 6 gallon red plastic fuel tank.

I'm debating adding another one but so far, I've been able to go about 10miles round trip up and down current/tidal flow and still be at about half tank.

 

No idea how boat will act if this huge livewell was filled. 

Itis the entire center bench seat area and has a divider inside it.

 

-------------------------

 

Pics of the damage!

 

3rd blade seems fine.

 

Insert your laugh emoji's now!

 

[WRB]

Repairable!

Tom

[Seafury]

14 hours ago, WRB said:

Repairable!

Tom

Thanks I will call around to see if/how soon I can get this done, and at what cost.

[Seafury]

Ok, I called around and the nearest prop repair shop seems to be almost 2 hours away in Charleston SC.

 

Local marina/shop can get me a new Solas SS in 2 days.

They want $247+tax for this one.

SOLAS New Saturn 12-1/2 x 13 RH 2331-125-13 stainless boat propeller (propellerdepot.com)

 

Is that what I need or do I need another pitch for SS as someone mentioned 12 I think someone said?

Yes, I will try to get mine off today or tomorrow to see what exact size it is.

I will also save my old prop and try to get it repaired later to have as a spare

 

 

[WRB]

Ship the prop along with photos, call for turn around time and price.

Most good prop shops have a loaner trail prop to answer your questions.

Tom

[Jig Man]

I didn’t notice anyone addressing the shaft.  You better keep a sharp eye out for lower unit leaks if you don’t replace it.  If you have insurance you probably have enough for a claim unless your deductible is high.

[TnRiver46]

A 40 horse? Just put any old prop on it. I even used to run a composite one with a 30 horse, just keep that boogered stainless on board for spare if it ran smoothly 

[TnRiver46]

Like @WRB, said , 13 P is probably standard, that’s what I have on my 50 HP. I know an old salty boat mechanic that started in Florida, he said the only way to really know which prop you want is to run them and compare. I even know some bass boat guys that arrange prop swaps at boat ramps so everyone can try different configurations 

[airshot]

After all these posts about props, hopefully you can see why there is not just " a prop" that can be recomended....way to many variables to consider.  You don't seem to concerned about finding the correct prop, so as suggested, just find anything that fits and go fishing.

[gim]

2 hours ago, airshot said:

After all these posts about props, hopefully you can see why there is not just " a prop" that can be recomended....way to many variables to consider.

 

X2, its headache I simply just got sick of trying to figure out.  In the end I just continued to use the factory prop that came with my boat when I bought it.