# Prop Help Tohatsu 50 4s



## jonny (May 1, 2007)

Got a 50 on my skiff now. Currently I have a Tohatsu(Powertech) 10.25 16p 3 blade no cup. Getting more squat and same speed as my Tohatsu 30 4s tiller I had before at 32 mph. It hits it quickly at 6k rpm. Was hoping someone may have a good starting point. I am looking for some stern lift and a bit more speed. Open to a cupped 4 or 3 blade. Was thinking larger diameter and the 14p range. I have nearly two inches of clearance. I do run a jackplate and tabs. And it is flat bottom. I definitely went backwards in performance over my 30😂
BTW my prop is for sale supposedly it came off a Whipray or Waterman(can’t remember) so may be good for a Conchfish/Eldora,ect


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## LtShinysides (Dec 27, 2018)

I've been running this one for close to 2 years and have been happy. Gets full rpms out of the motor and has good speed/all around performance. I get 34-38 mph in my Heron depending on load and conditions.


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## jonny (May 1, 2007)

Heron would probably be a good comparison size wise to my skiff.
And it’s 14p and the larger diameter which is what my thoughts were at.
Does this help lift the stern if you noticed?
Thanks


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## Salt (Mar 19, 2019)

What bolt hole is your engine mounted? What PT prop specifically? I’m running the MFS 60 on 3rd highest hole with a YBS stainless prop 10.25x16p 3 blade. I see 35-38 mph at 6k loaded. PT SCB is closest prop to mine and is stern lift. The MFS50 and 60 have similar performance from what others have posted. Should see more than 32mph at WOT for those prop specs.


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## LtShinysides (Dec 27, 2018)

jonny said:


> Does this help lift the stern if you noticed?
> Thanks


Not that I have noticed


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## coconutgroves (Sep 23, 2013)

Check out this thread that I started while researching the same thing for my Whipray:









Whipray and Tohatsu 50hp prop advice


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...




www.microskiff.com





Foreman props for the Tohatsu 50hp are 14p, 3 blade heavy cups.

Re stern lift..... what situation are you trying to solve? There might be other ways to solve it.


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## jonny (May 1, 2007)

Salt said:


> What bolt hole is your engine mounted? What PT prop specifically? I’m running the MFS 60 on 3rd highest hole with a YBS stainless prop 10.25x16p 3 blade. I see 35-38 mph at 6k loaded with minimal squat at holeshot. Best prop so far for the conditions fished and distances ran. PT SCB is closest prop to mine and is stern lift. The MFS50 and 60 have similar performance from what others have posted.
> Blind guessing, your engine may be mounted too low or perhaps your skiff is heavy and not trimmed out. 32mph at WOT is low for your prop specs.


I got it on a jackplate with tabs and tried all different height and trim. It’s very sporty on the way to 32mph. It did get a heavy load of 5 people up on plane cruising at 26mph. It had a 30 tiller and would hit 32 wot and cruise in mid 20s high and dry. I’m thinking some stern lift will free it up for another 6-8mph


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## Salt (Mar 19, 2019)

@jonny Worth a shot, try the SCB 15p or 16p. IMO, 14p will overrev. Follow up with us on your findings.


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## jonny (May 1, 2007)

coconutgroves said:


> Check out this thread that I started while researching the same thing for my Whipray:
> 
> 
> 
> ...


I actually had read that already. A lot of good info in there. Made me want a compression plate 😂


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## jonny (May 1, 2007)

Salt said:


> @jonny Worth a shot, try the SCB 15p or 16p. IMO, 14p will overrev. Follow up with us on your findings.


Yeah that’s a possibility for sure. Just trying to figure out why I needed a extra 20hp to run worse😩😂 anyone got a Foreman prop laying around?


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## Smackdaddy53 (Dec 31, 2012)

jonny said:


> Yeah that’s a possibility for sure. Just trying to figure out why I needed a extra 20hp to run worse😩😂 anyone got a Foreman prop laying around?


No but I can bring one next month...


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## mwolaver (Feb 6, 2014)

Look up a prop slip calculator on the interweb and plug your numbers in. Then call Powertec with that info. Their tech folks are pretty good. They steered me to a sternlifting prop for holeshot.


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## coconutgroves (Sep 23, 2013)

Salt said:


> @jonny Worth a shot, try the SCB 15p or 16p. IMO, 14p will overrev. Follow up with us on your findings.


Agreed here. I tried a 15p PT and it overrevved - based on the numbers I saw, I would have tried the 16p next, but still do not think it had the bite needed in cup for use with a jackplate ran high.


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## Salt (Mar 19, 2019)

@jonny I have a spare Foreman prop sitting here, but you’ll need a plate to run it. 12.5x14p, tops out at 34 mph. You will be disappointed, speed wise. Grip is another story.


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## Rick88 (Apr 15, 2016)

I ran the stock aluminum 15p and got 41mph in my 16 whip


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## jonny (May 1, 2007)

Rick88 said:


> I ran the stock aluminum 15p and got 41mph in my 16 whip


That’s moving along.
Was it the 11” prop and what RPM? With 15p you had to be right at 6k. I have seen several people post about the stocker being damn good on a skiff. Unfortunately mine came with a Tohatsu SS by PT


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## jmrodandgun (Sep 20, 2013)

Rick88 said:


> I ran the stock aluminum 15p and got 41mph in my 16 whip


Ditto. I tried a few different PT props and kept coming back to the stock prop. Bought a few spares and called it done.


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## Rick88 (Apr 15, 2016)

Looked back at my old post was actually running a 14p, not sure on other details It was the prop recommended by my dealer. I never ran a tach so no clue on the RPMs are at that time those motors were so affordable I wasn’t really worried about breaking one lol


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## jonny (May 1, 2007)

jmrodandgun said:


> Ditto. I tried a few different PT props and kept coming back to the stock prop. Bought a few spares and called it done.


Could you get me the numbers of exactly what prop you have?And what boat you running it on? I want to get a aluminum for a spare anyhow. I have never liked lugging a heavy ass SS around that most likely will never get used. So if it doesn’t work it’s my back up.


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## jonny (May 1, 2007)

Just found a chart on Tohatsu. The standard prop looks like 11.1 14p. That must be the one y’all have/had. That’s way bigger than this 10.25 SS one I have. I think I will grab one just for shiats & giggles to try. And it should get me close.


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## sjrobin (Jul 13, 2015)

In the Power Tec line, SCB series cup is the best for skiffs, in either three or four blade.


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## K3anderson (Jan 23, 2013)

jonny said:


> I actually had read that already. A lot of good info in there. Made me want a compression plate 😂


Where are you? I have a anti-cav plate lying around here in Tampa. It's the Cougar Marine one out of TX, but, I'm in FL. Boggs runs this one on his Spear tunnel with Tohatsu 50 and Foreman and it can run high with no slip or loss of water.


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## jonny (May 1, 2007)

K3anderson said:


> Where are you? I have a anti-cav plate lying around here in Tampa. It's the Cougar Marine one out of TX, but, I'm in FL. Boggs runs this one on his Spear tunnel with Tohatsu 50 and Foreman and it can run high with no slip or loss of water.


I’m just South of you in Englewood


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## jonny (May 1, 2007)

Should have my stock 11.1 14p to try tomorrow. Hopefully it will work out good.


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## LtShinysides (Dec 27, 2018)

I still have the stock prop it's 11x15.
It came with the boat when I bought it. I keep it for backup. It performed very well, I just prefer SS.


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## jonny (May 1, 2007)

Got my stock prop in late Friday. And ran it in horrid condition yesterday just to see If there were any improvements. And wow what a difference. The ass end is riding nice and high. No more wake boarders following me around😂 No water hitting the rear corners shooting over to my motor. Unfortunately it was very very rough in Charlotte Harbor. We had a strong wind out of the North. Which pretty much blows out everywhere. Then combined with a incoming tide it was legit 2-3’ with the occasional big roller just to check your ass. Not ideal conditions for a little light flat bottom skiff. There were just 3 boats under the bridge. And I only saw a few large CCs going about 15mph. So I couldn’t get a WOT speed check due to fear of lift off. I definitely got some air the two times I briefly tried solo. 😂 With me and my dad in it we did find a some what calm stretch for a few minutes. And we’re able to cruise at 31mph @5100rpm. Much better than topping out at [email protected] with the other. So definitely went in the right direction. Upper 30s is plenty fast for me. Hopefully this wind will die down soon and I can see what’s she got.


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## jonny (May 1, 2007)

Fixed one problem found two more😂
Still haven’t got a good top end run yet. I’m expecting high 30s. The wind has been hell on the harbor. But me and my youngest ran out after school. He always likes seeing me at school in the pick line boat in tow😂
We ran the harbor and fished the wall for a bit. It’s was pretty bad out there. But much better than last time. So I wanted to run up river to dodge the wind and see what we could get into.
I discovered that I now have a pretty bad slide in the turns at speed -20ish. I was tabbed down and hit a fairly sharp bend. We slid so hard I hard get off let it grip then punch it to stay out of the woods😂 It caught me off gaurd I must admit. Because I had made this turn many times with no issue at all. I thought maybe I had my inside tab down further. But I started intentionally making slide in a more open area to try some motor settings. But nothing other than slowing down worked. Going to have to try a 4 blade to see if it can keep me hooked up. I did run a 4 exclusively with the 30 except for a speed run with a 3 blade one day. So I’m thinking it was either one less blade or the extra 20hp or both. 
Another issue is now I have to tab down to prevent porpoising. Where before I never had a issue with the 30. I tried about every combo of height and trim to work around it. But had to use the tabs which isn’t that big a deal. But it just was never line that before.
This boat is happiest in the mid to upper 20s. Which just happens to be where my happy place is. So not concerned with losing 5 or 6 mph. So the search continues I think I will just buy cheap Solas props until I get close to the right one. Then go from there. I would buy a Foreman 3 blade if can find one. But anything else will be a 4 blade. Plus the 4 will give me even more stern lift. I may be flooding the classifieds with lightly used Tohatsu props soon I got two already 😂


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## Smackdaddy53 (Dec 31, 2012)

jonny said:


> Fixed one problem found another😂
> Still haven’t got a good top end run yet. I’m expecting high 30s. The wind has been hell on the harbor. But me and my youngest ran out after school. He always likes seeing me at school in the pick line boat in tow😂
> We ran the harbor and fished the wall for a bit. It’s was pretty bad out there. But much better than last time. So I wanted to run up river to dodge the wind and see what we could get into.
> I discovered that I now have a pretty bad slide in the turns at speed. I was tabbed down and hit a fairly sharp bend. We slid so hard I hard get off let it grip then punch it to stay out of the woods😂 It caught me off gaurd I must admit. Because I had made this turn many times with no issue at all. Going to have to try a 4 blade to see if it can keep me hooked up. I did run a 4 exclusively with the 30 except for a speed run with a 3 blade one day. So I’m thinking it was either one less blade or the extra 20hp. This boat is happiest in the mid to upper 20s. Which just happens to be where my happy place is. So not concerned with losing 5 or 6 mph. So the search continues I think I will just buy cheap Solas props until I get close to the right one. Then go from there. I would buy a Foreman 3 blade if can find one. But anything else will be a 4 blade. I may be flooding the classifieds with lightly used Tohatsu props soon I got two already 😂


I can “find” you a Foreman but it won’t be ready in time for me to bring it with me. You’ll get tired of fooling with props and bite the bullet before too long...


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## jonny (May 1, 2007)

That’s what I keep telling myself. I may be giving you a ring before long👍


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## Salt (Mar 19, 2019)

I also had bad trigger hair porpoising with the stock aluminum Tohatsu prop. Heard good things about the Solas Rubex C4, and they’re cost friendly. Keep us updated.


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## jonny (May 1, 2007)

UPDATE:
Well I’ve been running a Solas 3 blade 11.1/14 for a bit and it was a huge improvement over the PT. But still wasn’t where I needed it. It was scooting along with much more stern lift. With a nice attitude running flat with just a bit of bow lift. Only need one dab of the tabs and then was able to fine tune with the tilt, With two on board I was hitting 33.5mph at 5900 was hoping for a bit more speed. I just put a Solas 4 10.5/14 and it was even better. Riding just as it should high and dry good holeshot and grip running fully jacked. Except I lost about a thousand rpms from that extra blade. Runs at 30mph at 5000rpm which is now got me thinking about a 12 pitch to get some RPMs back. Or a semi cleaver to gain some. Definitely sticking with a 4 blade unless I can get a Foreman.

any thoughts on semi cleavers? I have heard drawbacks like poor holeshot and midrange. But I have seen a lot of small skiffs with them.


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## Smackdaddy53 (Dec 31, 2012)

Just get a Foreman and be done...that’s my opinion and you already knew that.


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## Salt (Mar 19, 2019)

Aren’t the SCB and YBS semi-cleavers?


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## jonny (May 1, 2007)

Smackdaddy53 said:


> Just get a Foreman and be done...that’s my opinion and you already knew that.


Anyone got any numbers on a Foreman with a Hatsu 50? I know the top end is going to suffer. Going 33 or 27 doesn’t make much difference in my usual day. When I do run across the harbor or way up river I will leave 5 -10 minutes earlier. Just curious about RPMs and stern lift with the 3 blade. My skiff is hooked up with the 4 blade. I was carving donuts with my brother yesterday. It was his first ride since I got the 50 and deck on it.


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## Smackdaddy53 (Dec 31, 2012)

jonny said:


> Anyone got any numbers on a Foreman with a Hatsu 50? I know the top end is going to suffer. Going 33 or 27 doesn’t make much difference in my usual day. When I do run across the harbor or way up river I will leave 5 -10 minutes earlier. Just curious about RPMs and stern lift with the 3 blade. My skiff is hooked up with the 4 blade. I was carving donuts with my brother yesterday. It was his first ride since I got the 50 and deck on it.


I just spoke with a client that has a 50 and I can call him and see what he’s seeing. The difference will be your not having a tunnel and his is a half carbon Chittum tunnel.


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## jonny (May 1, 2007)

Yep lots of variables not sure if that’s a fair measurement. Maybe ask what he sees with his fat friends riding. And I will compare with me solo unloaded and 1/8 of a tank 😂


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## Salt (Mar 19, 2019)

You asked about a 50, but with the 60 I saw 34mph consistently.


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## jonny (May 1, 2007)

Salt said:


> You asked about a 50, but with the 60 I saw 34mph consistently.


Thanks Salt
What hull and to be clear this is a Foreman 3 blade correct? And what RPM


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## Smackdaddy53 (Dec 31, 2012)

My buddy claims 32mph @ 5800rpm. I bet it will hit 34-35 if you really push it. He’s a bit conservative.


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## Salt (Mar 19, 2019)

jonny said:


> Thanks Salt
> What hull and to be clear this is a Foreman 3 blade correct? And what RPM


B2/Waterman hull, 3 blade Foreman with XXX cup and Foreman intake screens. 6k rpm.


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## Jason M (Aug 13, 2017)

Looking at mine I get 37 @5700 on my power tech scb3r16pys50


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## Smackdaddy53 (Dec 31, 2012)

The hull, how you run it and how high you mount the outboard are going to make a big difference in these numbers.


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## NealXB2003 (Jun 8, 2020)

Salt said:


> Aren’t the SCB and YBS semi-cleavers?


Scb is a copy of a ybs, but not a very good copy. Ive ran both back to back and the ybs is a better prop in every regard except price. Ybs has less slip, better holeshot and top end, less blow out in turns, e.t.c. SCB needs to be worked by a good prop guy to put it on a level playing field with a ybs.


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## Jason M (Aug 13, 2017)

NealXB2003 said:


> Scb is a copy of a ybs, but not a very good copy. Ive ran both back to back and the ybs is a better prop in every regard except price. Ybs has less slip, better holeshot and top end, less blow out in turns, e.t.c. SCB needs to be worked by a good prop guy to put it on a level playing field with a ybs.


Oh boy I may be going down a rabbit hole here. I run a Tohatsu 60 and power tech scb3r16pys50.

Do you think there's a YSB prop for that?


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## Salt (Mar 19, 2019)

Jason M said:


> Oh boy I may be going down a rabbit hole here. I run a Tohatsu 60 and power tech scb3r16pys50.
> 
> Do you think there's a YSB prop for that?


 Yes, I’m running the YBS 16p on a MFS60 and very happy with it.


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## Jason M (Aug 13, 2017)

Salt said:


> Yes, I’m running the YBS 16p on a MFS60 and very happy with it.


I guess I should say I'm looking for more top end speed. I don't have the need to jump shallow or really run that shallow.


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## NealXB2003 (Jun 8, 2020)

My experience is that a ybs is 1-2 mph faster than a comparable scb.


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## Smackdaddy53 (Dec 31, 2012)

Interesting tidbit...Jack Foreman designed some of these shelf props for PowerTech.


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## Jason M (Aug 13, 2017)

I was speaking with another person that has a Yamaha stainless on his Tohatsu 60, similar setup to mine. My only concern is that I don't specifically know how to tell if they are compatible props? It's not readily assistant on the Yamaha website.


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## Salt (Mar 19, 2019)

Jason M said:


> I was speaking with another person that has a Yamaha stainless on his Tohatsu 60, similar setup to mine. My only concern is that I don't specifically know how to tell if they are compatible props? It's not readily assistant on the Yamaha website.


I’ve have always matched the spline count and gearcase size to my lower unit and never had an issue swapping props. MFS 60 is 13 tooth spline and 3.25” gearcase. May need a different thrust washer to change the offset from the lower unit seal, depending on the prop.


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## Salt (Mar 19, 2019)

FYI, Powertech groups their props by gearcase size on their site.


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## Jason M (Aug 13, 2017)

Salt said:


> FYI, Powertech groups their props by gearcase size on their site.


Thanks Salt. My old skiff was a tank so I never paid much attention to learning this obviously.


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## Jason M (Aug 13, 2017)

Salt said:


> I’ve have always matched the spline count and gearcase size to my lower unit and never had an issue swapping props. MFS 60 is 13 tooth spline and 3.25” gearcase. May need a different thrust washer to change the offset from the lower unit seal, depending on the prop.


Interesting I didn't know that Power Tech listed my prop as a Yamaha prop actually. Both are the same size gear case


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## Jason M (Aug 13, 2017)

Update. I recently picked up a YBS and as @Salt mentioned it's a nice upgrade. More speed and lower RPMs


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## southernbassangler (Apr 27, 2021)

@jonny - have you made any other changes since? What are you running now? I have a 50 tohatsu on my 16 heron and with a pt but need to confirm the size. I can hit 31ish @ 5200 rpm but can easily over rev.


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## jonny (May 1, 2007)

southernbassangler said:


> @jonny - have you made any other changes since? What are you running now? I have a 50 tohatsu on my 16 heron and with a pt but need to confirm the size. I can hit 31ish @ 5200 rpm but can easily over rev.


Unfortunately not much to update. I’ve been slammed with three full rebuilds the last couple of months. I’m almost done with number two. When I get down to one I’m going to slow down to a 40-50 hour week so I can get out more and fish/test. I’m going to flip it soon and add the spray rails and do a slight tweak to the bottom. I think I can squeeze a bit more deadrise without compromising the draft. So I may just wait till I’m done before testing props again I am pretty close right now


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