Re-powering an AA BroadBill

S

Scott Gilliland

Active member

I have a long thread on a rebuild of an AA Broadbill here: Advice on sneakbox - AA Broadbill or MLB Wigeon. Last year I was looking to re power the boat. I have a 15 hp 4-stroke fuel injected Suzuki. I'm generally happy with the motor, it is light and fuel efficient and with me and the dog it runs great. But when I load it with a second person and a few decoys it is really sluggish. I have a hard time getting up on a plane and it performs poorly - even in light weeds. I was thinking of finding a used 2-stoke for it. The is an option to change out the ECM and a couple of other components to convert it to a 20 hp. I was thinking about this option and I found someone that will re-flash the ECM instead of buying a new one.​

I was a bit surprised when he quoted the price for reprogramming the drive ~$1000 CAD. A new 20 hp ECM is $4-500. He told me that the reflash is not the same as buying a new ECM. They do a lot more tweaking of the programming and they can boost the HP for this motor by 10 hp. Because I'm not interested in more speed, they suggest keeping the same diameter and pitch prop, but change to a 4 blade. This will give a better hole shot getting the boat up on plane sooner. ​

I do not know a lot about motors ... the hull is rated for a 25 and I'm wondering if if there are concerns about wear and tear by pushing that motor by 5 HP beyond its designed capacity. Here is a link to the company that does the re-programming (http://www.htmcoating.ca/outboard-efi.html). ​

​

Any thoughts appreciated.​

 
Scott

There is no replacement for displacement. I ran my AA Broadbill with a 15hp Evinrude and it was underpowered. I upgraded that motor to a 25hp Johnson and it was a whole new boat. Plenty of power with two guys and gear. Maybe you could sell your 15 and find a second-hand 25. I bet you could upgrade to a 25 hp used motor for no more money than the upgrade you are considering. Going this route there is no risk you will be disappointed. The 25 on that hull is proven.
 
25 is the way to go carrying a load. When I first bought my Blackjack (similar design & weight). I used a Merc 2 stroke 25 on it from a previous jon. It would fly but also would carry a load easily which seems to be important to you. I sold that blackjack as kids got to age to go and out grew boat. I bought and redid a 14' Steury and used same 25 on it for a while. Several years latter I bought back the Blackjack and by that time 25 was long gone and I replaced with a 2 stroke Merc 15. Serious lack of power for that hull with blind installed and decoys and retriever. With 2 adults it barely would plane after pushing water for a long stretch. Definitely search for a 25 2 stroke to save a bit of weight.
 
Thanks Guys. I was convinced that going back to a 25 hp 2-stroke was the the right motor of the boat. A real advantage for the 4-stroke I appreciate is I can use the same gas in my larger boat and my generators. I was intrigued by the option of getting ~25 hp out of the 15 Suzuki. For most of the 4 strokes the 9.9, 15 and 20 are all the same motor, when you jump to a 25 it's in a different family. The 25 4 stroke is about 40 lbs heavier than the 15 which could be a real advantage.

I chatted with the owner of the business. The reprogramming only pushes the motor ~ 5 hp beyond is it's design. He said that the original programming of the ECM has to work across a variety of fuel grades and to get the extra HP from the motor the programming is optimized for higher octane fuels (93 Octane). I'm not sure why it would cost so much to refresh the drive, apparently it takes only a few minutes. It seems like a good option, but as Eric says, a used 25 is proven and might be cheaper.
 
I,m growing kind of fond of the 4 stroke 25 Tohatsu I have on my 1648 jon. Starts easily on cold morning with the electric start, and sips gas. Easy enough to service yearly. I still have a couple 2 strokes also in use though. A 15 merc on the 1436 and a Etec 90 on the 2072. That Etec sips gas as well. Your going to love the 4 stroke come cold weather , especially if electric start.
 
Well, I've gone back and forth about reprogramming the ECM to potentially increase the output from the 15 hp 4-stroke Suzuki to ~25 hp. This requires fuel with octane rating of at least 89 -- I use mostly premium anyways. The advantage is 25 hp with a <100 lb motor. Moving up to a 25 hp 4-stroke increases the weight increases to 125-135 lbs. I've been surfing outboards for the last year and nothing really interesting came up.

Yesterday I came across a 30 hp 3 cylinder short shaft Yamaha. It's a 1995 model year and looks in great condition. It's a little over 130 lbs putting it in the same weight range of the 25 hp 4-strokes. The maximum recommended HP for the Broadbill is 25 hp. From what I understand the only real difference between the 25 and 30 is the carb. I think a negative is I'd have to carry more gas with the larger 2 stroke.

Any thoughts.... good/bad?

Thanks
Scott
 
Scott Gilliland said:
Well, I've gone back and forth about reprogramming the ECM to potentially increase the output from the 15 hp 4-stroke Suzuki to ~25 hp. This requires fuel with octane rating of at least 89 -- I use mostly premium anyways. The advantage is 25 hp with a <100 lb motor. Moving up to a 25 hp 4-stroke increases the weight increases to 125-135 lbs. I've been surfing outboards for the last year and nothing really interesting came up.

Yesterday I came across a 30 hp 3 cylinder short shaft Yamaha. It's a 1995 model year and looks in great condition. It's a little over 130 lbs putting it in the same weight range of the 25 hp 4-strokes. The maximum recommended HP for the Broadbill is 25 hp. From what I understand the only real difference between the 25 and 30 is the carb. I think a negative is I'd have to carry more gas with the larger 2 stroke.

Any thoughts.... good/bad?

Thanks
Scott
Click to expand...
Many 25,s and 30,s are built on same block. My Tohatzu 25 is that way, so weight is the same. Your boat will definitely scoot with that 30 on there. A more realistic comparison would be to look at average weights of a 25 from years your boat was built. Give you an idea of what is safe on transom now. The 3 cylinder 30 Yamahas were known to make power well . Those 30,s may have been built on 40 block but not positive.
 
From what I can see there seems to have been models in those years: 2 and 3 cylinders. Both models had 25 and 30s on the same blocks, but the 2 cylinders were lighter. I'm not all that concerned about speed. My larger boat carries the maximum hp and I love it. It cruises at 3300-3800 RPM, I rarely run it over 4000. But it's there when I have load. The 15 is great within it, add decoys and wet dog and I'm not impressed. Also that 4 stroke really does not like running in the weeds, and we Rin in a lot of weeds.
 
Scott

Those three cylinder 25/30 Yamahas are great engines and still very desirable. If the compression is good and it looks like it was cared for I'd snag it. Your Broadbill haul ass with one on the back. You will never wish you had more throttle and will likely run the boat at 1/2 to 2/3 throttle where you get peak efficiency.
 
Scott Gilliland said:
Well, I've gone back and forth about reprogramming the ECM to potentially increase the output from the 15 hp 4-stroke Suzuki to ~25 hp. This requires fuel with octane rating of at least 89 -- I use mostly premium anyways. The advantage is 25 hp with a <100 lb motor. Moving up to a 25 hp 4-stroke increases the weight increases to 125-135 lbs. I've been surfing outboards for the last year and nothing really interesting came up.

Yesterday I came across a 30 hp 3 cylinder short shaft Yamaha. It's a 1995 model year and looks in great condition. It's a little over 130 lbs putting it in the same weight range of the 25 hp 4-strokes. The maximum recommended HP for the Broadbill is 25 hp. From what I understand the only real difference between the 25 and 30 is the carb. I think a negative is I'd have to carry more gas with the larger 2 stroke.

Any thoughts.... good/bad?

Thanks
Scott
Click to expand...
The 25 and 30 three cylinder Yamaha's are my favorite motor! I own a bunch of them. You're better off just going with 30 because it weighs exactly the same as the 25. It just is not as restrictive exhaust as the 25 and it has more robust carburetor jetting.

They are easy to work on amazing power to weight ratio. Plus fairly lightweight in the stock configuration.

if you decide you want to swap on electric start, it's easy enough to find a old control motor and scaveng the parts from it to add to a stock pull start motor. I've done this several times myself.

Most of these motors are at least 30 years old now. So have your due diligence when inspecting one. Check Compression, pay special attention to the lower unit, as well as the oiling system if it is intact or has been removed for premix..
 
Scott

A few states over in Arkansas they have WMAs with 25 hp restrictions. There is now an entire culture of three cylinder 25 outboard enthusiasts who modify the motors and get 50+ hp from all the excess 25 hp displacement. I won't get into the problems they've created in this thread, but the bottom line is these motors are highly desirable and command a steep price in the used outboard market. Sadly, they are vanishing at a fast rate due to the abuses they are put through.
 
Eric Patterson said:
Scott

A few states over in Arkansas they have WMAs with 25 hp restrictions. There is now an entire culture of three cylinder 25 outboard enthusiasts who modify the motors and get 50+ hp from all the excess 25 hp displacement. I won't get into the problems they've created in this thread, but the bottom line is these motors are highly desirable and command a steep price in the used outboard market. Sadly, they are vanishing at a fast rate due to the abuses they are put through.
Click to expand...
What could possibly go wrong with this whole situation?????
:unsure:
 
Eric Patterson said:
Scott

A few states over in Arkansas they have WMAs with 25 hp restrictions. There is now an entire culture of three cylinder 25 outboard enthusiasts who modify the motors and get 50+ hp from all the excess 25 hp displacement. I won't get into the problems they've created in this thread, but the bottom line is these motors are highly desirable and command a steep price in the used outboard market. Sadly, they are vanishing at a fast rate due to the abuses they are put through.
Click to expand...
Alright fine….. I did tune this 30hp to a 40hp with some mods…LOL but that is 100% correct I know guys that have really supped these 3 cyl up to crank out some amazing power. Probably easier to buy a 25hp sticker for the cowling for many :LOL:
 
I’m very sorry I missed that sale. I had a meet setup and got a notification that it was sold. There is another on the market, but it is significantly more. It’s been listed for awhile… I’ll keep looking for a deal.
 
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