2000 Mercury 225 ProMax ECU Question

**freeebird** · 07-23-2015, 02:59 PM

I hadn't noticed until today, but the ECU off my 2000 225 ProMax has a factory decal showing part number 824003A0. The CDI decal shows 824003A32D. Does anybody know which ECU originally came with this motor?

**tux974** · 07-23-2015, 05:03 PM

The CDI decal shows 824003A32D

If it is a 20" motor it would have come with an A32. 15" motor an A23.
It looks like CDI put the A32 curve according to their decal.

**TEXAS20225** · 07-23-2015, 06:06 PM

Tony interesting note , i bought a 225 promax that was blown around a month ago ,powerhead was on a 200 fishing mota midsection, and brain was a no sticker ecu which is always scary (when you know how some people think) but a quick read with my DDT which i brought with me before i bought it , it also read 824003A0 on the small gold decal on the top of the brain, but it read to be a A23 from the ss models go figure huh

**freeebird** · 07-23-2015, 06:24 PM

Originally Posted by tux974

If it is a 20" motor it would have come with an A32. 15" motor an A23.
It looks like CDI put the A32 curve according to their decal.

Mine is a 20", but why would they use a different ECU on a 15"?

I too figured CDI put the A32 curve in there. I've owned this motor about a year, and when I ran a history on it, the ECU had been replaced under warranty. That's the only thing that showed up. I'm guessing the A32 is still the best curve to go with as I'm going to have to send this one off to Simon to be repaired. I've had zero luck finding a used A32.

**whipper** · 07-23-2015, 06:33 PM

I had both acus also. i cant recall now why the SS one was different but it had something to do with one running leaner or richer if i recall?

**freeebird** · 07-23-2015, 07:02 PM

Originally Posted by whipper

I had both acus also. i cant recall now why the SS one was different but it had something to do with one running leaner or richer if i recall?

Yep, each ECU variation has a different fuel curve, but when it's the same exact motor, I can't see where shaft length is going to matter. It obviously does, but I'd like to know why.

**myron** · 07-23-2015, 07:24 PM

the ss had a different exhaust plate, that is why the curve was chaged

**freeebird** · 07-23-2015, 07:51 PM

That makes sense.

**tux974** · 07-23-2015, 07:56 PM

Originally Posted by myron

the ss had a different exhaust plate, that is why the curve was changed

Exactly! The SS came with a 1pc plate and the 20" came with the 2pc plate. Different tuners and cooling.
Not saying the A23 would not work on a 20" and visa-versa. I have seem many combos that have actually worked without rime or reason.

**freeebird** · 07-23-2015, 08:02 PM

Originally Posted by tux974

Exactly! The SS came with a 1pc plate and the 20" came with the 2pc plate. Different tuners and cooling.
Not saying the A23 would not work on a 20" and visa-versa. I have seem many combos that have actually worked without rime or reason.

I've talked to some knowledgeable folks who say other fuel curves can be better depending on boat weight etc. One guy said an A6 would result in better fuel economy mid-range. I'm all ears if anybody has any hands on experience with trying different versions. Mine spends 98% of its time running around 5,000, and I'm not at all opposed to saving some fuel.

**tux974** · 07-23-2015, 08:03 PM

Originally Posted by freeebird

Mine is a 20", but why would they use a different ECU on a 15"?

Answered this ? above

I too figured CDI put the A32 curve in there. I've owned this motor about a year, and when I ran a history on it, the ECU had been replaced under warranty. That's the only thing that showed up. I'm guessing the A32 is still the best curve to go with as I'm going to have to send this one off to Simon to be repaired. I've had zero luck finding a used A32.

Not easy finding that box. You may also come across a box the will say R32. That means that is was remapped at Mercury.
Tony Brucato says that the A17 has a very good curve.
All A6 boxes I have come across have been good boxes. They are actually the first 225PM boxes,95,96.

**freeebird** · 07-23-2015, 08:09 PM

My brother's 225PM has a R32. I believe his is either a 98 or 99 model. I read about it being remapped at Mercury, but does that mean it went in with a different fuel curve?

I know the A17 was a remapped A12 that was burning up some motors, but I think that was in 96. Were there any real changes in the 225 between 96 and 2000 that resulted in the need for a fatter curve?

**TEXAS20225** · 07-23-2015, 08:45 PM

i bought my first 225 pmax in 1995 it had the A6 on it it was the best stock brain as far as rpms ive ever owned it would wrap to 7000 any time you needed it , my good buddy bought a sister boat to mine in 95 also it was also an A6 but i would not twist to 6700 what im saying is two identical stickered ecu wont necessarily run the same

tony has had lots of that stuff ive owned several and rebuilt quite a few they just aint the same ecus ive had 150 ecus out run 200 ecus on the same mota

**tux974** · 07-24-2015, 05:36 AM

Originally Posted by TEXAS20225

i bought my first 225 pmax in 1995 it had the A6 on it it was the best stock brain as far as rpms ive ever owned it would wrap to 7000 any time you needed it , my good buddy bought a sister boat to mine in 95 also it was also an A6 but i would not twist to 6700 what im saying is two identical stickered ecu wont necessarily run the same

tony has had lots of that stuff ive owned several and rebuilt quite a few they just aint the same ecus ive had 150 ecus out run 200 ecus on the same mota

Hard to figure out as to the why...

I have also found 7 petal front 200 run extremely well on the 225PM.

freebird, the A12 for sure had the recall. I have seen A17 run extremely well and for years!
Mercury found that putting a fat setting/curve would protect their motors because these motors were run hard by all buyers and also being made to spin up pretty good.....

Have you talked to Brucato? Ask him about the A17.

NOTE: I'm not an engine builder

, do this as a hobby so info I'm giving you are my findings or experiences after having a few of these 225PM. Actually have 4 fresh complete with different boxes in my garage as we speak/type, only motor I play with!
I'm actually running an A32 and an A17 on my own personal motors.