# Whipray and Tohatsu 50hp prop advice



## coconutgroves (Sep 23, 2013)

Hoping to get some advice from people who have tried different props and pitches on this setup.

2015 Whipray Classic with a new Tohatsu 50hp 4 stroke. Atlas jack plate and ShawWing compression plate. I fish Texas that has miles of knee deep flats - a jack and compression plate is essential.

I have a Foreman 14p, 3 blade heavy cup. I've ran Foreman on my other boats - very great getting up skinny and running with the jack all the way up. Can stay on plane in low MPH.

I am getting about 31 mph (27 kts) fully jacked up (prop shaft directly inline with bottom of hull) at 6k rpm once I trim up a bit. Without trim, it hits about 5,700 rpm. That is 2 anglers with a fairly light load. Really good. But it porpoises like a mofo. Not just a little bounce, I am talking it could cause you to get out of control if you didn't know how to handle it.

Yeah, I know, use tabs. But those tabs do cause drag and slow down the boat. My B2 did not need any tab on plane and I could trim it out. Any trim up on the Whipray and I am going to take off like a float plane.

So I am thinking to try a stern lifting prop and see if the shallow water performance is good enough, I can get just as good or better top end, and also use less tab.

I realize there is a trade off between best top end and best holeshot in skinny water. I've been doing this a while.

Hell's Bay recommends the Powertech SCB (stern lifting prop) in 13p. Nettles here in Austin suggested me going to a 15p. Now I can try a 14 and see how it does, then always trade it in.

The compression plate supposedly (per Kevin at Stiffy) causes you to lose about 300 rpms since it is so effective in channeling water, so he recommended lowering the pitch to increase the rpms. That is why the 15p doesn't sound right to me.

Any advice is appreciated.


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## whoislang (Jul 29, 2020)

Go with your plan for the 14SCB, then report back. But I can already tell you it wont like the jackplate as much as your foreman.


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## Sublime (Oct 9, 2015)

I had a B2 also. Sponsons. You'll never get it to lift the bow much and, as you know , the faster you go, the flatter it would run.

I'm following. My Conchfish will have a Tohatsu 60 as well.


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## Sublime (Oct 9, 2015)

He's running a tunnel , but maybe @Tx_Whipray can chime in









And so it begins...Repower and refit my 1999 Whipray


So after almost selling my Whipray and building a new skiff, I've decided to keep and refit her. The first step of the process was a repower. After pouring over the pros and cons of all the 15" shaft 50 HP outboards on the market (ha ha), I decided on the Tohatsu 50HP 4 stroke. I picked the boat...




www.microskiff.com


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## Sublime (Oct 9, 2015)

Instead of a stern lifting prop, I think you need a bow lifting prop. A good bow lifting prop would get the bow up and keep it there. Your bow is lifting now, but it can't stay there, so it falls back down, then it goes back up and falls back down and on and on.


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## coconutgroves (Sep 23, 2013)

Sublime said:


> Instead of a stern lifting prop, I think you need a bow lifting prop. A good bow lifting prop would get the bow up and keep it there. Your bow is lifting now, but it can't stay there, so it falls back down, then it goes back up and falls back down and on and on.


Hmmmm, interesting... haven't heard that. Just talked to PT and they said the SCB stern lift should help with the porpoising, so these two are at odds with one another.


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## Sublime (Oct 9, 2015)

coconutgroves said:


> Hmmmm, interesting... haven't heard that. Just talked to PT and they said the SCB stern lift should help with the porpoising, so these two are at odds with one another.



Oh, it is entirely possible I am wrong.


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## whoislang (Jul 29, 2020)

Yeah I dont know if thats the right philosophy.... Thats like saying when you start porpoising to trim up more


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## coconutgroves (Sep 23, 2013)

I am going to try the SCB 14p and if I get some slipping while jacked up, but if I like the performance, I can have cup added.

One last point - I've ran solo without much weight in the front, but also with another person and a loaded Yeti up front with more fuel. Porpoising was the same.

I've seen some move the battery to the bow and they said it helps some, but I am not quite ready to do that yet.


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## Rich11111 (Jun 6, 2018)

If you tuck the engine further in won't that fix the porpoising? If it's all the way tucked then you may need negative transom wedges. I had the same problem with my Chittum. Added negative 5 degrees and it solved my porpoise problem.


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## coconutgroves (Sep 23, 2013)

Rich11111 said:


> If you tuck the engine further in won't that fix the porpoising? If it's all the way tucked then you may need negative transom wedges. I had the same problem with my Chittum. Added negative 5 degrees and it solved my porpoise problem.


I think the jack plate setback may have increased the porpoising. But when I run super shallow, I don't want my skeg tucked all the way down - I need to trim up and get the plate horizontal with the water as much as possible. I can do this without porpoising now since I run at lower speeds and have tab. I am reluctant to add wedges because of this, and actually am surprised you needed them on the Chittum. Not knocking it, but that's the first I've heard they need wedges. What model, engine and jack plate do you have?

I have the SCB 14p on the way and will water test in 2 weeks. PT believes that the stern lifting on the prop will help, but may not solve it. And if that's the case, then so be it. I'll move the battery up front and may even put on a larger ShawWing for increased drag (would offset the tabs to an extent). I have the medium on there now and it's big, but man does it work.


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## Rich11111 (Jun 6, 2018)

coconutgroves said:


> Chittum. Not knocking it, but that's the first I've heard they need wedges. What model, engine and jack plate do you have?


The Laguna Madre 2 with Hatsu 60Hp on Bob's Jackplate. It was suggested I get them and it was night day improvement with get up and stopped the porpoise. I was told by someone who has one on order that they are standard now.

On my previous boat I considered putting the battery up front for balance but I didn't do it since it would be with the gasoline. I hope that won't be your issue.


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## Smackdaddy53 (Dec 31, 2012)

Rich11111 said:


> If you tuck the engine further in won't that fix the porpoising? If it's all the way tucked then you may need negative transom wedges. I had the same problem with my Chittum. Added negative 5 degrees and it solved my porpoise problem.


I want to run your boat after my pickup install if you will allow it.


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## Rich11111 (Jun 6, 2018)

Smackdaddy53 said:


> I want to run your boat after my pickup install if you will allow it.


Sure


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## Smackdaddy53 (Dec 31, 2012)

Sublime said:


> Oh, it is entirely possible I am wrong.


You know I won’t hold back. You are wrong. If you have porpoising issues and stick a bow lifting prop on it you’ll magnify the issue. A stern lifting prop will counter the porpoising and you won’t have to run trimmed down and tab down all the time to correct it.


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## Smackdaddy53 (Dec 31, 2012)

coconutgroves said:


> Hoping to get some advice from people who have tried different props and pitches on this setup.
> 
> 2015 Whipray Classic with a new Tohatsu 50hp 4 stroke. Atlas jack plate and ShawWing compression plate. I fish Texas that has miles of knee deep flats - a jack and compression plate is essential.
> 
> ...


I’d like to run your skiff too and see what’s going on. That is not a prop issue, it’s got to be weight distribution or a combination of other factors causing it. I like to run different setups to see how they act. Not saying you don’t know how to run your skiff but sometimes it takes a crazy mofo to push it and find the sweet spot if it exists. I love tweaking boats.


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## sjrobin (Jul 13, 2015)

Post transom view pics with the Jack plate at full down and full up. To trim a 2019 Pro perfectly, with a Shaw wing, the starboard tab will be down a little to lift my weight. The engine trim will be out a little for optimum speed/rpm and the Jack plate will be about 2 inches up, depending on how it is mounted.


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## mwolaver (Feb 6, 2014)

PT steered me to a stern lifting prop. I am happy with it. But these boats are prone to porpoise and the only thing that really controls it is the tabs. I am convinced that boats with 20" transoms porpoise even worse that 15s. I have had one of each. In the end, speed is a secondary consideration for me, behind hole shot and low speed operation. BUT... I get 31 mph with my 40/4 yamaha and got 33 with the first "all around" PT prop. With the 50, you should be at 33/34 all day, I would think. Good luck with your search. Mark

Edit: my buddy runs an older waterman with the 50 tohat...uses the original aluminum stock prop. Runs like a rap'd ape.


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## K3anderson (Jan 23, 2013)

How close are you to Jack? I would go out with him if you are nearby and let him run the skiff.


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## HunterOnFly (Apr 15, 2020)

I run a BTX (B2 without sponsons and way different liner) with an SCB in 12 pitch. 50 Yamaha 2 stroke, Bob's FlatsJac, 33 MPH by myself. It doesn't have trim tabs. I have never gotten any porpoising by myself while trimmed all the way out. In fact it rides very flat, but that could be due more to weight distribution than the stern-lifting prop.


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## coconutgroves (Sep 23, 2013)

K3anderson said:


> How close are you to Jack? I would go out with him if you are nearby and let him run the skiff.


Not close enough to question his prop! Actually, I've bought a few props from him and have been to his shop. But he makes one prop for this engine, and told me to get a large plate but instead I got a medium, so I don't want him to be disappointed me with. 

Don't get me wrong.... I can trim and tab this out, run the jack plate all the way up and get 31 to 32. That is really good. And it is smooth riding too - I can ride a hard rail and not blow out even with the jack plate all the way up. It is awesome. I am just trying to balance the skiff a bit more to not rely so much on tabs.

Maybe I am just trying to reach perfection, but this is also a learning experience and I like tuning stuff.


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## sjrobin (Jul 13, 2015)

coconutgroves said:


> Not close enough to question his prop! Actually, I've bought a few props from him and actually have been to his shop. But he makes one prop for this engine, and told me to get a large plate but instead I got a medium, so I don't want him to be disappointed me with.
> 
> Don't get me wrong.... I can trim and tab this out, run the jack plate all the way up and get 31 to 32. That is really good. And it is smooth riding too - I can ride a hard rail and not blow out even with the jack plate all the way up. It is awesome. I am just trying to balance the skiff a bit more to not rely so much on tabs.
> 
> Maybe I am just trying to reach perfection, but this is also a learning experience and I like tuning stuff.


32 mph is good for a Foreman cup. There is perfect speed trim and there is a perfect shallow planing trim. Best to mark the jackplate for each position. If the prop stays connected with the Jack plate all the way up, the engine is not mounted high enough.


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## coconutgroves (Sep 23, 2013)

sjrobin said:


> 32 mph is good for a Foreman cup. There is perfect speed trim and there is a perfect shallow planing trim. Best to mark the jackplate for each position. If the prop stays connected with the Jack plate all the way up, the engine is not mounted high enough.


It is good, but the porpoising is not. And on the jack plate, pretty much the best spot is all the way up for best speed and rpms. I had way more play on my B2 with a Bobs, although I would typically only need 1 to 1.5" - I'd run at 4.5, get up at 5.5 to 6, then go back down to 4.5. That was engine mounted at the highest hole.

The challenge with a Whipray is the lower poling platform plus the large cowling on the engine. I can raise the engine another bolt, which I may do, but the cowling will hit the platform with the jack all the way down and trimming up will hit the platform. This platform has the puck light mount right above the engine which causes more an issue.

I had to do the platform again, I would have it raised 2" and also offset the puck mount for extra clearance - that Tohatsu cowling is a beast.

I will also add, I am not in love with the Atlas, even with the reinforcement. I've had to tighten the bolts again all the way around since I could see it shifting around when going up. It is also very slow on the rise.


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## Smackdaddy53 (Dec 31, 2012)

Hell’s Bay rigs and builds their tunnel hulls exactly the way they rig their non tunnels which makes zero sense. The platforms are too low, the motors are mounted too low and as soon as you raise it where it needs to be to get the prop where it runs best the cowling is hitting the platform unless you get a 15” shaft.


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## sjrobin (Jul 13, 2015)

The best lower unit/prop position for speed/efficiency, even with a tunnel, is not at the highest position. The caveat would be the prop/size/pitch/cup. Tab adjustment is a bump on the switch. One bump up or down on the starboard tab where you sit on a side console is a lot of change, just like a tiller version. 
More tab is needed on a non sponson skiff to prevent porpoise


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## devrep (Feb 22, 2009)

is the whipray classic 16 ft? my 16 waterman will porpoise if I give it very much trim bow up. already runs with most of the hull out of the water with the little trim I can give it before it begins to porpoise. wide open I have maybe 3 ft of the stern in the water when conditions are flat. at the bow I have yeti 45 with ice and food/water, trolling motor, 2 small bluetop batts, fuel tank. small anchor and a few other things. at the stern I have a small bluetop starter batt and hatsu 50 which is really too much motor weight for this boat.


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## Capt.Ron (Mar 5, 2014)

Pull the gray pin out, trim down


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## coconutgroves (Sep 23, 2013)

devrep said:


> is the whipray classic 16 ft? my 16 waterman will porpoise if I give it very much trim bow up. already runs with most of the hull out of the water with the little trim I can give it before it begins to porpoise. wide open I have maybe 3 ft of the stern in the water when conditions are flat. at the bow I have yeti 45 with ice and food/water, trolling motor, 2 small bluetop batts, fuel tank. small anchor and a few other things. at the stern I have a small bluetop starter batt and hatsu 50 which is really too much motor weight for this boat.


Yes, 16'4".


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## JJones (Nov 14, 2019)

Following


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## coconutgroves (Sep 23, 2013)

Ok, so I ran the Powertech finally. It isn't the right prop setup for sure.

I was delayed because they didn't hub it right - it was a 1/2" short, and I didn't have a splined spacer washer, so I had to source that.

I went with the 14p SCB 3 blade - it got me less top end, but also was too high in RPMs. Just so happens that I added NMEA to my skiff (another thread coming soon) and I was getting alarms from my Simrad when going over 6k. Top end was 26 knots - on the lower side, but also around 6,200 RPMs. That is 30 mph, but this was also in freshwater, which I see slower numbers (salt is more buoyant). I did have the Foreman at 29.5 knots loaded in the salt - that is 34 mph - really good for a 50hp with 2 guys at 180lbs each on a Whipray.

It did reduce the porpoising by a good amount - I really didn't have to use tabs at all, however, as I jacked up the engine to the same level I run with the Foreman prop, RPMs increased, but not really top end. It needs more pitch - I think a 16p would be better - it would drop the RPMs by about 300, then allow me to jack and trim it to reach 6,000 RPMs.

However, the Powertech didn't not perform well at all getting the boat on plane with the jack plate up. It is a stern-lifting prop, made for flat bottom boats, but it just lacked the punch to get up quickly. But, it did not blow out in turns and also with the plate all the way up - I thought that would happen and did not. I think the compression plate keeps enough water around it where it prevented that from happening.

For comparisons, here is the Foreman (larger prop) and the Powertech. Not knocking the PT at all - they make good stuff, I just think for my combo with a jackplate, compression plate, and getting up skinny, the Foreman is a better option.











The Powertech footprint:











The Foreman footprint - much more prop, but that also does load the lower unit more:










And the short hub where I needed a spacer:










Next steps? I am going to just fish what I have, then move some weight around during the winter. I want to move my battery to the bow to see if that makes a difference. I am also going to raise the engine one more bolt, although that places it where it will hit my platform if trimmed up too much.


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## devrep (Feb 22, 2009)

not sure why anyone would expect grip at high lift or holeshot out of a PT SCB. nothing about that prop lends itself to those requirements.


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## coconutgroves (Sep 23, 2013)

devrep said:


> not sure why anyone would expect grip at high lift or holeshot out of a PT SCB. nothing about that prop lends itself to those requirements.


Yeah, I had not run one before but wanted to try it. They claim it is a stern lifter (which it did) and help flat bottom boats plane better (I did not experience that). If it had good top end and solved the porpoising issue, I was going to add cup to it that would have helped with getting up and also being jacked up.

Also, this is recommended prop and pitch from Hell's Bay for this boat and engine. I was not impressed by it all where I would recommend it. Maybe Jack just makes the honey badger of props and nobody else can compare.


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## Surffshr (Dec 28, 2017)

I have to say that I don’t know, but it sure looks like that Shaw plate is backwards. At least the one I had many moons ago was installed the other way. Probably makes no difference.


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## Smackdaddy53 (Dec 31, 2012)

Surffshr said:


> I have to say that I don’t know, but it sure looks like that Shaw plate is backwards. At least the one I had many moons ago was installed the other way. Probably makes no difference.


It is backwards, whoever notched it did it wrong. 
Coconut, the Foreman is going to be hard to beat all around especially with that little shelf prop.


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## Salt (Mar 19, 2019)

Coconut - 16P should be right for that setup. Running a YBS16p and it’s right at 6k on hole 3. No cav plate.


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## coconutgroves (Sep 23, 2013)

Smackdaddy53 said:


> It is backwards, whoever notched it did it wrong.
> Coconut, the Foreman is going to be hard to beat all around especially with that little shelf prop.


The Shaw Wing was installed exactly like this - these pics are from their site - it is not my boat but my install matches this. I've also been to the shop in person and Kevin showed me how to install.




















What specifically is backwards on mine? I don't see any issue.


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## NealXB2003 (Jun 8, 2020)

I have a hull that is prone to porpoise. I tried the scd3 as well (larger diameter version of the scb, but same blade profile). It did cure the porpoise, but it slipped too much. On top end, slight turns, e.t.c. I would have liked to try the scd4, the 4 blade version, to see if the extra blade would have helped with the slip, but kept all the positive traits of that prop. The scd/scb props are a copy of a Yamaha black stainless, but not a great copy. The ybs has much better grip. Runs higher on the jackplate and never turns loose in the corners. It is a more expensive prop though, and only available in a couple of limited pitch ranges.


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## devrep (Feb 22, 2009)

I had the large shaw wing on my waterman/hatsu50 and it did practically nothing for holding more water around the prop at high lift. when I took it off it performed exactly the same. sold it and got a Tran Sport and night and day difference.


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## devrep (Feb 22, 2009)

this was how I was told to mount mine by Kevin.


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## Smackdaddy53 (Dec 31, 2012)

coconutgroves said:


> The Shaw Wing was installed exactly like this - these pics are from their site - it is not my boat but my install matches this. I've also been to the shop in person and Kevin showed me how to install.
> 
> 
> 
> ...


I’ve cut/installed three Shaws and had 15 skiffs in my shop since January that had them. It looks like a couple of them are like yours. I guess they are different designs for some reason. 
These photos are all different skiffs at my shop.


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## coconutgroves (Sep 23, 2013)

@Smackdaddy53 - I see what you were thinking. Some of the designs had a longer vertical edge that was more aft - even the install video on their site shows this design. Mine is definitely installed correctly - this is my third one.

Here are two more shots - you can see the front of the plate does come down more than the back (aft) of the plate.


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## Smackdaddy53 (Dec 31, 2012)

coconutgroves said:


> @Smackdaddy53 - I see what you were thinking. Some of the designs had a longer vertical edge that was more aft - even the install video on their site shows this design. Mine is definitely installed correctly - this is my third one.
> 
> Here are two more shots - you can see the front of the plate does come down more than the back (aft) of the plate.
> 
> ...


I never noticed it before, learned something new for sure!


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## Surffshr (Dec 28, 2017)

This has to be the most complete photographic record of Shaw wings in a single thread.


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## coconutgroves (Sep 23, 2013)

Surffshr said:


> This has to be the most complete photographic record of Shaw wings in a single thread.


Hahahaha - I'll get more this week - she is in storage. It is much prettier than those - caulked it and shaved the bolts off.

You guys scared me that I noob'd my wing and installed it incorrectly! Thought my street cred was going to take a big hit! 🤣


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## Surffshr (Dec 28, 2017)

I’m glad I put the IDK disclaimer in as I REALLY didn’t know, but who the efff did?…until now that is.


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## Smackdaddy53 (Dec 31, 2012)

Surffshr said:


> This has to be the most complete photographic record of Shaw wings in a single thread.


I have a few more but figured I covered the bases. One Fury and the rest are Chittum LM1 and LM2s.


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