# Thoughts on the Tohatsu 30hp vs 50hp



## Bluwave (Nov 3, 2014)

I'm trying to decide between these two motors to re-power a 16 Waterman. I originally intended to go for the 50hp, but have recently had a thing for the 30hp. 

The 30hp has my attention because it weighs 50lbs less, but what kind of performance numbers would I see? Does anyone have experience with the 30 Tohatsu? Also, I need a short shaft so the etec and suzuki are out of the question. 

Any advice is always appreciated.


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## jrasband (Jul 12, 2010)

That's a tough call I've been on that hull with a 40hp Yamaha 4 stroke and 50 hp Yamaha 2 stroke and cruising over 30mph was very nice for long runs. I could see being unhappy with a 30hp on that boat if you've got the need for speed.


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## CodyW (Jan 26, 2016)

Just a few things. Are you doing long runs? How shallow are you going? Are you going to pole the boat?


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## jmrodandgun (Sep 20, 2013)

A 25% reduction in weight is not worth the 40% reduction in horse power. Not that there is anything wrong with the 30, it's a great motor, but if you're doing it for draft then you're doing it for the wrong reason. I don't have a pencil in front of me but I'd be willing to bet it would be somewhere around 1/4 of an inch difference in draft.

Speed is a different conversation. In Louisiana 10 or 12 mph increase in speed is huge when you're running 20 miles in one direction. I would be shcoked if you saw much more than a 12 mph increase by jumping up to the 50. You can assign a number to each motor by (pitch x rpm)/(gear ratio/1056)= Theoretical top speed. This will tell you how fast each motor is capable of traveling. You can fine tune it with other equations but this will give you a good starting point.

With the 50 you're going to see high 30's maybe even reach 40 at WOT. The 30 is going to be high 20's and will flirt with 30-31 at WOT.


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## Hunter (Mar 31, 2016)

have a 30hp tohatsu on my bossman karma. 
I get between 26&28 with 2 adults,full cooler and a full tank of gas at wot 
I've sniffed 32 with the wind at my back and going with the tide once

In a few years I'd like to re power with the 50hp. 
I know the boats rated only for the 30hp but when looking at the weights on some of the other 30's made by other manufacturers the tohatsu 50hp still weighed a couple lbs less. 

Although I haven't looked to see if the 50hp would even fit on the karma or if I'd be breaking any laws or creating any real safety issues but that's a question for a later time. 

Very happy with the 30hp tohatsu though.


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## Tx_Whipray (Sep 4, 2015)

In a lifetime spent around boats, I've never once heard a person say "yea it's a great boat, I just wish I had less horsepower".


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## Bluwave (Nov 3, 2014)

Thanks for the advice guys. I like the idea of shedding some weight, but there are those days after work when really I have to hustle to get to my spots. For those times a 30hp might be a hair slow.

I think someone needs to make a 40hp (4-stroke) that weighs 150lbs...


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## jmrodandgun (Sep 20, 2013)

If you got rid of the side console, trim tabs, and picked up a manual start/trim 30 you will start saving enough weight to matter.

Side by side I doubt two boats rigged the same would have much, if any at all, draft difference between the 30 and the 50. You will probably be able to move a few things around inside the boat to negate that 50 pound difference.


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## jonny (May 1, 2007)

Unfortunately it seems near all manufactures have abandoned the 15" market. The Tahatsu is the best/only choice☹


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## mwolaver (Feb 6, 2014)

I have a 40/2 merc on my 2002 waterman. According to the gps, my boat touched 36 mph once with the former owner. I normally run it around 4200 rpm, which is 21 knots under the right conditions, on long runs. In my personal opinion, this boat is not comfortable traveling over 30 mph. It's cool to be able to do it, I guess, but it is no boat for long runs at high (relatively speaking) speeds. Also, remember the platform height. Some of those new Tohats require raising the platform. Looking forward to seeing your choice. Mark


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## devrep (Feb 22, 2009)

I have a 16 waterman tunnel hull with hatsu 50 2 stroke. With a very heavily cupped PT 3 blade , 2 men, loaded (including 24v batts in front) I'm getting 33-34 mph. By myself I'm getting 36. I suspect if I put a speed prop on I would come close to 40.


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## devrep (Feb 22, 2009)

BTW I used to have a 2001 merc 25 2 stroke on the boat which is probably at least as powerful as a 4 stroke 30 and weighed 114 lbs. Top speed was 28 wide open, 1 man with gear. Cruising speed without killing the motor was 22-23 mph.


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## devrep (Feb 22, 2009)

Hunter said:


> have a 30hp tohatsu on my bossman karma.
> I get between 26&28 with 2 adults,full cooler and a full tank of gas at wot
> I've sniffed 32 with the wind at my back and going with the tide once
> 
> ...


It's not just about the weight. Don't overpower that skiff. If you ever lose control momentarily or have to go hard over at high speed it can get ugly fast. Esp if it's a tiller. I've been on a Karma and really like them but not a good boat for a 50.


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## Hunter (Mar 31, 2016)

devrep said:


> It's not just about the weight. Don't overpower that skiff. If you ever lose control momentarily or have to go hard over at high speed it can get ugly fast. Esp if it's a tiller. I've been on a Karma and really like them but not a good boat for a 50.


Cool. Thanks for the input. Mines a side console but your probably right about the safety factor. 
I've had the boat for almost a year and couldn't be happier with the way it has performed for my needs.


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## Tx_Whipray (Sep 4, 2015)

devrep said:


> I have a 16 waterman tunnel hull with hatsu 50 2 stroke. With a very heavily cupped PT 3 blade , 2 men, loaded (including 24v batts in front) I'm getting 33-34 mph. By myself I'm getting 36. I suspect if I put a speed prop on I would come close to 40.


How is the hole shot with that 50? If I end up keeping the Whip, that will be the motor I repower with.


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## devrep (Feb 22, 2009)

hole shot is pretty much instant, I'm sure the prop helps with that.


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## Tx_Whipray (Sep 4, 2015)

if you had to get it up in an emergency, how much water do you think you need? Do you have a cavitation plate on it?


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## devrep (Feb 22, 2009)

I'm running a PT SWC3. I can get on plane in a little over a foot with the tabs down. I don't do that often though as I don't want to beat up the grass. I can get on plane really shallow by putting tabs down and slowly increasing speed. Takes about 30 or 40 feet but is a mellow way up. I had an SWC4 on for a while and it really jumped up but the 3 blade is a little faster top end. 

I was running a Shaw Wing for about a year but took it off a while back.


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## Tx_Whipray (Sep 4, 2015)

thanks! One more question...do you have a jack plate on the boat?


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## devrep (Feb 22, 2009)




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## Tx_Whipray (Sep 4, 2015)

what a great boat.


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## IRLyRiser (Feb 14, 2007)

You can get a 40 merc in 15" shaft too. Just have to swap gas assist trim in tilt it comes with with a power trim and tilt kit. Just FYI. Tohastsus are great motors as well.


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## Saltychicken (Jan 18, 2017)

devrep said:


> I have a 16 waterman tunnel hull with hatsu 50 2 stroke. With a very heavily cupped PT 3 blade , 2 men, loaded (including 24v batts in front) I'm getting 33-34 mph. By myself I'm getting 36. I suspect if I put a speed prop on I would come close to 40.


Are you still enjoying your tldi? Any issues or praise that you would care to share?


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## devrep (Feb 22, 2009)

Saltychicken said:


> Are you still enjoying your tldi? Any issues or praise that you would care to share?


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## devrep (Feb 22, 2009)

No issues at all. Love this motor. Have about 90 hours on it now. I also have a 2014 90 TLDI on my other skiff.


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## Saltychicken (Jan 18, 2017)

devrep said:


> No issues at all. Love this motor. Have about 90 hours on it now. I also have a 2014 90 TLDI on my other skiff.


Thanks for making my decision easy!!


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