I was attending a powerboat racing conference today and Mercury Marine just announced the introduction of a new performance upgrade for some of their four stroke engines in the 175HP and above outboards.
It is called "Boost" programming and enhances the hole shot and midrange performance of the applicable engines by up to 20% or more.
It is done by a ECU program change that can be done at an authorized Mercury Outboard dealer. Cost is expected to be around $250.
It does not enhance or improve top speed performance but can greatly improve acceleration from hole shot to top end speed.
It also does not entail any prop changes or any other modifications and does not affect the warranty of the engine.
This should not be confused with the ECU flashing that is available from Hydro Tech or Nizpro. This is offered by Mercury Marine themselves.
I am attaching a link from Mercury that has all the details. Folks I spoke with at the conference that have run engines with the new "Boost" upgrade say it's pretty impressive.
https://www.mercurymarine.com/sp/en/gauges-and-controls/controls/boost

I have a Yamaha SHO 250 and the company Nizpro has an ECU flash kit that will take any of the SHO 200 - 300 HP outboards to 332 HP, unfortunately the kit costs $1700. I have considered doing it but the cost is pretty high, at $250 I easily would. It's nice to see a company charging a reasonable amount to basically tune a motor electronically.

Hydro Tech in Missouri are also a Yamaha service center. They do the ECU flash as well. They can flash your existing ECU or sell you a new Yamaha ECU that has been flashed. Both with the same HP increases as Nizpro.
Hydro Tech also offers two types of flash options. One gives you more top end performance but doesn't raise the rev limiter. So you will normally need to go to a higher pitch prop. The second raises the rev limiter so you can turn much higher rpms.
Nizpro sells you the software and you then flash your ECU.
Both Hydro Tech and Nizpro flashes give more HP and more top end speed.
Mercury Boost just gives faster acceleration with no top end speed improvements.
ETA: The Yamaha SHO's outperform the Mercury's in hole shot and acceleration and Mercury has lost sales because of that. They are offering this programming upgrade to, imho, try to match Yamaha's acceleration performance.

If this is that good, no chance it stays $250. It will be $500 before the first quarter is over.

Interesting. As you know, I'm in the process of getting two new 225s. Sounds like it only changes things when at WOT? No difference in cruise efficiency at mid range RPMs?

It's a tune they do that probably wastes a bit of fuel to maximize the power curve.

As someone that daily drives a Jeep that I also wheel I'm gonna guess that Venn diagram of 175+HP outboard owners and those concerned with marginal fuel 'waste' looks like a cartoon view through binoculars.

It will reduce range somewhat if you run at high rpm.

The tune is to give increased performance from low end (hole shot) and mid range acceleration to whatever RPM you desire. So if you are sitting still and go full throttle it will give a better hole shot and get you to whatever speed you desire quicker.
It does not increase your top end speed or max rpm's over what your engines are developing now.
Their techs said that the only time it will cause more fuel consumption is the initial acceleration. Once you obtain your desired rpm or cruise speed the fuel consumption should actually be improved…..according to them.
Mercury has lost some market share to Yamaha and Suzuki due to the much better low end and mid range performance of those brands on high HP engines than Mercurys like engines.
Mercury has always emphasized their marketing toward superior top end speed characteristics…..and not so much towards the low to mid range performance envelopes.
Their R or Racing series engines are examples of that…..badging those engines with the "Racing" logo on them to appeal to the egos of the end users.
Mercury's run fast but their low end and mid range performance suffers because of that.
The trend by end users has been towards not caring so much about top end speeds….and putting more emphasis on low and mid range performance as the priority…… which is the strengths of Yamaha and Suzuki.
Also all the new Mercury engines listed built after Q2 of 2026 will have the "Boost" tuning as standard.

At $250 why dont they just make it standard. Seems silly to have it as an option. Maximize what you have and sell it. There is no down side. Marking up a $30,000 motor to $30,250 wont hurt sales.

Yes sir. Good point. I just addressed that in the last sentence in my above post. All those listed engines will have that as the standard tuning on engines manufactured after Q2 of 2026 according to Mercury.

Gunny if you were me and wanted the extra hp in my SHO which company would you go with? Nizpro is Australian which may or may not matter. I live on the TX coast so I can't transport it to any of the places and would have to do it myself?

How many hours are on your SHO? Is it still under factory warranty?
If you don't mind posting an email, I can send you some information.

Got it. Can delete.

Sooo, how what if a 200Hp outboard is on a production boat with a USCG hill rating maximum of 200HP and this boosts it over the rating?

I can get away with ignoring USCG because my custom builds are considered "experimental" and it doesn't apply. I guess it can't be sold retail with an overpowered outboard but if you "repower" it after the fact with a tune update then that's no different than putting a higher HP outboard on the hull aftermarket.

That may be why I'm a few cases they can't be sold yhis way right from the dealers.

The rating plate is a CYA for the manufacturer.

The HP rating and number of passengers is not enforceable.

You can have as much horsepower as you dare to bolt on and as many passengers as you have life jackets for until it is sitting on the bottom.

NMMA Certified boats have their horsepower rating plates determined by actual performance and handling test that the boat must pass…rather than the coast guard rating that is based strictly on dimensions and weight of said craft.
So at least for NMMA certified boat brands the placard actually means something.
Sadly one is opening himself up to one expensive liability if you exceed the HP rating and/or carrying capacity weight on the placard and ever have an accident that has injures or kills someone in this day and age.
Makes it really conducive for a personal injury or wrongful death attorney to prove negligence….and to give an insurance company an easy out to deny coverage.
I have testified as an expert witness on many cases involving these instances and seen the monetary cost involved.
I miss the old days when nobody really cared.

I want that done on my 150 pro xs two stroke

I have a 2019 200 Pro XS on my Mako 21, it's already WAY more than we need I can't imagine needing a faster hole shot!