replacing ECM for more HP , thoughts?

[dhsofficer]

I have read many places that the ecm on a 90merc can be reflashed to 115 hp.
Could I not just buy a 115hp ecm.
Thoughts?

[babock]

ECMs are very expensive. Cheaper to flash

I called that guy that does the flashing. I decided it was not worth it. A lot of the increased HP is due to the increased RPM limit. I have my doubts if it would increase torque enough that I would even be able to change props.

Have you talked to the guy? My engine is the Yamaha power head version. Yours is likely the Merc version. Can they do yours?

[kryptonite]

I've been throwing this around also.

I have a 75 hp 4 stroke, I know I can go to a 90hp just by removing a baffle in the air intake, and a ECM flash. However, there are differences in the 115. The gearcase ratio is different, I think. Also the air intake manifold is different on a 115. Although mine is a 2006 model, things could have changed. I went online to a parts diagram and looked at the differences between the different hp's.

Doubt you are really gonna see much difference though. Maybe 2 mph?


Here's the company that can reflash them. You could call and ask.
http://www.simonmotorsports.com/ecu/optiecu.htm

[Bryden24shp]

The ECM reflash is worth every penny. The fuel injection pulses and trims are smoothened out, the air/fuel ratio is tightened up, because they run so fat from the factory. The timing advance and curve is straightened. The exhaust temps actually go down, instead of up, which is usually seen when leaning out an engine. That's an engine killer! You'll notice much better fuel economy, and hole shot, right off the bat. The old saying that a dealer will see the reflash, is completely untrue. Your rev limiter will be reset to allow a few hundred more RPM, but the RPM gains realized are from the enhancements. Mine cost $850 to have Eric Simon do. I talked to Eric for along time before doing it, because I heard of all the "bad things". Its already paid for itself in fuel savings, in 3 years. To gain the full benefits, I need to run 91 octane. That gives me 318 dynode horsepower from my 225. Running 87 octane, is about 285 hp. Still a 60 horse improvement over stock. A stock ecm will run 1500 to 1800 bucks. The reflash 850.
My honest opinion.... DO IT!!! Its super cheap horsepower plus a fuel saver.

[crookedlaker]

I have been looking at the same thing with my 90.
The newer Mercs are identical from the 75 to the 115
the 75 does have a air restrictor that can be removed.
I think it is 2007 and newer units that are merc built and are the same
engine except for the ECM code. I am not sure about the new command thrust engines.
The last time i spoke to them was about a month ago and they did not have the code
finished for my engine, they said it would be a couple of months yet.
The cost will be $650 when done. I will be getting it done when it is available.

Mike

[BobG]

I'm still holding on to the link to Simon Motorsports for one simple reason:

At 7,500 feet elevation, my 115 doesn't generate 115 horsepower. It generates...

...let's see, 3% loss per 1,000 feet of elevation = 0.97 ^ 7.5 = about 80% = 91 horsepower.

Well, that sucks! So they say they can get me up to a real 115.

[Bamaman]

Bryan's great horsepower increase was on a Verado--a supercharged motor. Horsepower gains on any tuned engine are much greater on supercharged and turbocharged motors than just a fuel injected motor.

I would only trust Simon to reflash my motor's ECM. Screw with the "trim" and the balance on the engine's fuel injection takes experience only he has on marine outboards.

It's doubtful that flashing a 75 hp or 115 hp would be worth the gains in horsepower. But things would be different on a Verado. I'd just like to see a comparision of before and after on a 250 hp Yamaha SHO that's so popular with bass boat owners.

[Bryden24shp]

The speed increase wasn't that great. Just jumped up 2 sizes in prop and gained 6 mph. I agree with Kryptonite, you may see a few MPH increase But the economy, holeshot and midrange throttle response are just fantastic! A 40 mph throttle punch will set you back in the seat!
Bama's right, that supercharger has a lot to do with my gains. And that supercharger whine? It just gives ya a Woodrow!
My next engine choice would be a SHO. I wonder what gains Eric could get out of a 250, also. Good question!

[babock]

To gain the full benefits, I need to run 91 octane. That gives me 318 dynode horsepower from my 225. Running 87 octane, is about 285 hp.

Two questions.

Does your engine have knock sensors so that it can advance the spark to take advantage of the increased octane?

How did you verify your HP? Did you have the engine connected to a dyno before and after?

[Bryden24shp]

Can't answer the first, Bama??? Do I?
The second is easy. I had it on a prop shaft Dyno after the burn. 321, on 93 octane at 6800 RPM's. I propped it to 6400, where it was 318. I didn't want to be in the limiter at WOT. Did not have it done before, the burn. Kinda wish I did, but at $150 a pop to run it on the dyno...na! Ooh, I used the word POP and dyno in the same sentence.... NOT GOOD!

[Bryden24shp]

Yep, it does have knock sensors... I googled it!

[jediger]

Bryden24shp

If memory serves, you had an etec on your old Manitou. Can you flash the ecm on an etec 2 stroke as well? The website for Simon only lists 4 stroke Johnsons. Have an Etek 250ho (G1)

[Bryden24shp]

Good memory! I asked Eric about the Etec's when I had mine, at that time he did not, they were write protected. I just went to his website and see that he still doesn't. Must not have figured a way around them yet. I do know how to get another 35 to 40
HP out of it, but it involves cutting the exhaust housing and running it above water, taking the baffles out of the intake. Drilling holes through the air box. Stuff that I wouldn't want to do... Well???

[jediger]

Good memory! I asked Eric about the Etec's when I had mine, at that time he did not, they were write protected. I just went to his website and see that he still doesn't. Must not have figured a way around them yet. I do know how to get another 35 to 40
HP out of it, but it involves cutting the exhaust housing and running it above water, taking the baffles out of the intake. Drilling holes through the air box. Stuff that I wouldn't want to do... Well???

UMMMM... Maybe not! Thanks.

[babock]

but at $150 a pop to run it on the dyno...na!

That's only 6 pairs of ez fenders!