Help choosing 15hp dingy motor

The friendliest place on the web for anyone who enjoys boating.
If you have answers, please help by responding to the unanswered posts.

huruta

Senior Member
Joined
Jan 9, 2022
Messages
126
Vessel Make
2006 Nordic Tug 32
We have an 18 y/o 2-stroke yamaha 15hp outboard motor. We inherited it 2 years ago with our Nordic Tug 32 and have done all the preventive maintenance, taken it to a local shop that found nothing wrong and it continually dies when we are out in it. We are really tired of trying to fix this thing and simply don't trust it. It sounds like people have loved this motor, but given all the trouble it's given us it means it is time to retire it. It's time for a new dinghy outboard. We have never bought an outboard but here are some considerations:
  1. No to electric b/c we want to take it to AK and have plenty of power and we are on a mooring buoy all summer and e-charging isn't appealing
  2. We want it to be durable with parts available in AK, we are currently in WA
  3. We have heard a 15hp can be a backup for our NT 32 in an emergency (true?)
  4. Looking at Yamaha and Suzuki but open
  5. Yamaha 15hp is a carb motor, Suzuki 15hp is EFI
One question is whether an EFI is better for intermittent use. Realistically, we aren't using it much in the winter and we are both still full-time employed. We've been putting about 125 engine hours on our NT 32 per year so less for a dinghy o/b. We are not especially handy so less maintenance and less headache is desired.

Another question is where one can get reviews/reliable information about outboards. Such information seems hard to find. Are there independent outboard reviews of these? Suggestions & opinions welcome.
 
I prefer injection vs carbs ever since I had to de-gunk 3 motorcycle carbs to get them running. Never had to fix a gummed up injection system.
 
Suzuki and Tohatsu both offer EFI. Ours is a Suzuki 20-hp, electric start and trim, the second one actually. (Sold the first, 15-hp, with dinghy, along with the last boat).

Our experience has been decent, although we learned you do need to flush the motor religiously after use in salt water.

I've had Johnson and Johnson/Suzuki carb'd outboards before; tired of that.

-Chris
 
I asked the same question a couple years ago (Thread is HERE - Best 15hp outboard these days?). I went with a Tohatsu 20hp because it's essentially the same as a 15hp. Best I can tell, Tohatsu EFI has overtaken Yamaha as the go-to engine in this class.

BTW - I went with Electric start/tilt so my wife could easily run the engine too. Glad I did - it starts easily. I also went with a LFP start battery (AntiGravity) so near zero parasitic loss. So far, so good.....

Good luck with whatever you decide.

Peter
 
A dozen or so years ago I bought an 18hp Tohatsu from this site:
They seemed to be the best deal I could find at that time. Electric start, remote shift.
I was able to talk them into shipping one directly to my home. YMMV.
 
I have a 10 year old 9.9 Suzuki. It has been a very good engine. I use it for salmon trolling all summer. I have no idea of the hours but it is a bunch. If I were buying a new one I might go with the 20hp as they are the same engine. But it would have to be EFI as those just start and run better. It would be a Suzuki for me as I feel the best dealer in this area sells them. I think all the new ones are good so it is dealer quality that makes the sell.
 
We have heard a 15hp can be a backup for our NT 32 in an emergency (true?)

Luckily I have never had to do this but looked into it and the answer seems to be "mmm, yes at a couple of knots" ... which is better than nothing but pretty limited with PNW currents. Could certainly help with maneuvering though.

Best approach is said to be a side tie with the dinghy, and steering with main boat rudder. There's a Boat Galley blog post Emergency Motor When Traveling by Boat - The Boat Galley and this YouTube with good illustration

Sometime I plan to tie the dinghy alongside and try it.
 
Thanks all for your responses. This is helpful. Appreciate the video about how to use a dinghy as an ER motor! Will look more carefully at the Tohatsu. Definitely find the EFI more appealing given all the carb problems we have had with this older 2-stroke.
 
Suzuki and Tohatsu both offer EFI. Ours is a Suzuki 20-hp, electric start and trim, the second one actually. (Sold the first, 15-hp, with dinghy, along with the last boat).

Our experience has been decent, although we learned you do need to flush the motor religiously after use in salt water.

I've had Johnson and Johnson/Suzuki carb'd outboards before; tired of that.

-Chris
Chris - Could you expand on the need to flush with motor after salt water use? We are on a mooring buoy all summer in the Salish Sea so won't be able to do this; wondering about your experiences and the consequences.
 
I bought a new 15 hp Suzuki for my skiff here in NJ mainly because the dealer is right down the road. I put about 30 hours on it since new and did the first oil change myself. It starts easily with a 230 mca lawn tractor battery. Rope starting is more difficult than an old 15 hp 2stroke Evinrude that it replaced. Fuel economy is excellent.
 
Chris - Could you expand on the need to flush with motor after salt water use? We are on a mooring buoy all summer in the Salish Sea so won't be able to do this; wondering about your experiences and the consequences.

Apparently they have a tendency to "salt up" around the cylinder head if not flushed after salt water usage. And mostly we grew up with outboards on midwestern rivers, so the idea of flushing hadn't been high in my mind.

OTOH, much of our learning curve was also probably about low usage; our first Summer with the first engine, we probably used it only about 4-5x, and didn't flush at all. (I figured low usage....) Eventually, the next year (ditto no hurry to flush), salt build-up around the cylinder head had to be chopped out with an ice pick.

So... now we know that...

Flushing is actually very easy, either with muffs on the skeg intakes or with a direct connect to the flush port. I suspect 5 minutes would be fine. In our case, the dinghy is mounted on our swim platform, the flush port happens to be facing in, a hose from our freshwater washdown spigot is about a 4' run... given flow rate through the orifices, I'd guess that's maybe only a couple or three gallons...

I've read that folks who use their outboard every day don't have the same symptoms.

I don't know if the Tohatsu is any different/better in that regard.

-Chris
 
We have a Tohatsu 20 hp EFI, rope start. Diane can start it. Reliability has been spot on as we begin our fourth season. As noted above, the 20 hp is the same weight as the 15 hp.
A friend bought a 9.9 Suzuki for use on his pontoon boat last season and has been very happy with it.

Rob
 
Interesting comments on flushing. I wonder if anyone else has had salt build up issues.
OP: What type of dinghy to you have? I bought a portable solar panel for my epropulsion outboard if that makes any difference for your mooring situation.
 
I asked the same question a couple years ago (Thread is HERE - Best 15hp outboard these days?). I went with a Tohatsu 20hp because it's essentially the same as a 15hp. Best I can tell, Tohatsu EFI has overtaken Yamaha as the go-to engine in this class.

BTW - I went with Electric start/tilt so my wife could easily run the engine too. Glad I did - it starts easily. I also went with a LFP start battery (AntiGravity) so near zero parasitic loss. So far, so good.....

Good luck with whatever you decide.

Peter
This.

Unless you are super concerned about cost or if your tender is only rated for 15hp max, there is really no reason to buy a 15hp 4 stroke. Suzuki, Merc and Tohatsu build both the 15hp and the 20hp on the same block. Same weight, size etc. It will be a good bit heavier than your old 2 stroke 15hp with a little less low end torque, so you might really appreciate the extra HP.

I had a 20hp Suzuki for 8 years, it was great, but traded it for a 20 hp Merc electric start last year because I like some of the Merc features better and it was $500 cheaper. My dealer (who is also a friend) sells/services both Suzuki and Merc. He said the reliability of both motors is exactly the same, both are good.

I like the Merc a bit better so far, but like I said, both are good motors.

Doug
 
Interesting comments on flushing. I wonder if anyone else has had salt build up issues.

I read somewhere (cruisersforum.com, I think) that another person did... but I don't know complete circumstances. I've also read that many who use their dinghies constantly haven't had much of an issue. (We don't use ours often.)

Can only say that I've become more likely to flush after use, these days. With the newer engine.

-Chris
 
The tohatsu has a garden hose connection that is up high making it easy to connect the hose and shoot water through it. It seems like it would be easy to do in the water.
 
+1 for the Tohatsu 20.
 
Thanks Chris, for you response, and to all the additional people who have chimed in. Tohatsu is now a definite contender. A follow-up question:

Our Achilles dinghy is rated for a 15hp and 1060 lbs total and is probably from 2006 when most 15hp probably weighed less. Our old 15hp motor was 80lbs and these newer ones are 104-6lbs (Tohatus/Suzuki, 15" electric start and manual tilt). I don't see a weight limit on the dinghy for the outboard, just a hp limit. We also have the motor on a Seawise Davit and the davit plate probably adds a bit of weight. Should this additional weight on the transom be of concern?
 
It would help if you were more specific on what Achilles you have i.e. model, size etc. Maybe someone on here has the same dinghy and can recommend an outboard size.
 
This is the model we have albeit older. We will probably stay within the specs and get a 15hp
 

Attachments

  • IMG_0735.jpeg
    IMG_0735.jpeg
    67.3 KB · Views: 26
I just bought a suzuki 9.9 and love it. Smooth and quiet. Same as 15 and 20. Electric start. Perfect for me. As to flushing I have been religious about it on outboards over the years and never had an issue. However on my previous small Yamaha outboard for my tender, I went a season without flushing and took it apart prior to putting it away. Lots of caked up salt in all the water passages. I am in the process of setting up a freshwater hose to run salt away through my new suzuki after each time it gets pulled out on the seawise davits. More salt in one season on a tender with probably 10 uses than I would have expected. My belief is the drying out between uses is hard on them.
 
Have you considered a smaller outboard like a Tohatsu 9.8, it weighs in around 82 pounds. If you are not using all the power of your 15hp I'd consider going lighter. If you find you are just running your 15hp at 1/2 throttle you could maybe consider a smaller lighter outboard. If you guys like going longer distances at higher speeds or carry more than 2 people then I'd stick with a 15.
 
Also consider the hydroplaning fins to add to the outboard. With the additional weight of the 4 stroke, it will help keep the nose down when going slow through the anchorage and get you on plane quicker.
 
The tohatsu has a garden hose connection that is up high making it easy to connect the hose and shoot water through it. It seems like it would be easy to do in the water.

That's like the flush port on our Suzuki, too. Haven't tried it while in the water, yet. Might be reachable.

-Chris
 
Anyone hooked up a garden hose to a fresh water sink in bathroom/kitchen of trawler to flush outboard? Enough pressure? Presume even 3 gallons/short flush could help.
 
Last edited:
We are on our first boat and old dinghy motor has never worked, 90% hassle on that motor — our Nordic Tug has been trouble free. I don’t feel like we’ve ever experienced the power and feasibility of a good dinghy outboard so we are very excited to get a new one! I think we do want a 15hp for our longer dinghy trips when in remote British Columbia and Alaska and the security of some semblance of a back up motor if ever needed.
 
Before I built a flush adapter for my 8hp Johnson I used to tie a 5 gallon bucket up around it and to the flush that way. Kind of hokey but it worked. If you have a flush adapter then just hook it up to your fresh water washdown and it will work fine.
 

Latest posts

Back
Top Bottom