Are the 2.5 EFI any good for recreational boating or best for just racing?

[pcrussell50]

I’ve only had carb motors in my 13 years as a boater. A handful of bubbleback V4 crossflows. And a few years later a 2.0 150 which bags become our family’s main recreational boat motor.

But Now you guys finally have:
-sold me on Merc V6’s
and
-Made me curious about 2.5’s which seem to be the official motor of S&F
-Made me curious about EFI 2.5’s

With the high performance bias around here, I have to ask… Are the EFI 2.5’s still good for family recreation boats or are they like a delicate temperamental thoroughbred?

And before I keep wasting everybody’s time is there a post that’s not 1700 pages long that takes us through each generation of Merc V6, with displacement, horsepower and EFI or carb?

I have an actual paper shop manual for my 1987 2.0 150. It covers up to the 2.4 200. Isn’t one of those EFI? And was it any good for daily reliability?

-Peter

[Greg G]

You don't need to do any research. Just find a Promax 225 or later 225X and you will be happy. Both models are EFI and make about 245 ish horsepower and are lightweight. Someone will correct me but they ran from 1996 to 2004.

[moatorbotin]

my 2.5 200 EFI has been said by many to be "the 2nd best motor Merc ever made" - it idles all day long if I want it to, pulls the kids tubing/skiing, etc. I just make sure to "clean it out" at some point through the day by getting it up into the 4500+ RPM range for a hot minute to make sure that I'm not leaving behind a ton of unbrunt fuel/oil/carbon build up, etc. in the motor.

I'm told my 225 pro max is the "best motor mother merc ever made" - Idle's and behaves almost exactly like my 200, but pushes my boat faster. Same thing, I just make sure to let it breathe before parking the boat for the day.

The Nicasil motors (260/280) ...... (there are other nic models as well....) require a bit more care. Rings more frequently, etc.

[Brad Zastrow]

I personally would stay away from the 260 and 280 for recreational boating. The nic motors are very unforgiving and tend to need frequent rebuilds that are expensive. The 225 Promax 2.5 is a great engine.

[David]

Short story. The V6 began as a 2L, then a 2.4, and finally the 2.5. All the civilian motors, 135, 150, 175, and 200 weigh pretty much the same, except for the Optimax that are heavier. As you go up in displacement you get more torque. Lots of these came with carbs or fuel injection. Most were carbed.

The high performance 2.5 liter engines, 245 carb, 260 EFI, 280 all weigh less, burn a lot of gas, and need new rings every 100-150 hours. On a light boat for speed these can’t be beat.

The 225 Promax was for many the sweet spot. It would rev to 6800 but with steel sleeves, it could run 1000 hours. The 225 PM was also lighter.

The Merc 200 had various changes over the years. The FF block version seems to be the most desirable.

[John S]

I used my 260 for skiing. It worked okay, but as stated, it's a gas guzzler, and is shorter on the maintenance schedule than a steel sleeve. Depending on how many hours a year you boat, the rebuild might not be that big of a deal to you. They are rediculously fun motors to have.

That said, a few things done to a promax l, and you can have a really stout motor. I saw one with 260 electrics and stock internals hurt a few 260/280 guys feelings at a race. Not mine, because I take pride in winning the first back to the trailer race.

[Greg G]

..... And before I keep wasting everybody’s time is there a post that’s not 1700 pages long that takes us through each generation of Merc V6, with displacement, horsepower and EFI or carb?

I have an actual paper shop manual for my 1987 2.0 150. It covers up to the 2.4 200. Isn’t one of those EFI? And was it any good for daily reliability? -Peter

Two more things worth thinking about. Even if you find a Promax 225 or a 225 X or even a run of the mill 200 EFI 2.5 which I believe was last produced smartcraft capable in 2003 you are still talking about 20 year old motors. Important that you have someone with knowledge somewhat close to you to service them. On the 260/280 hi end stuff the guys "who know" are dying off and much harder to find. Also, to throw something else at you (nor really knowing your set up) might also be worth looking at a new 3.4l motor from Merc with warranty if the performance does not call for Promax or X 225 weight or grunt.

[LakeFever]

How much speed difference would there really be all things being equal save for 200FF vs 225 promax?

[David]

I left out the 2.4 EFI, Bridgeport, etc as I don't know anything about them. Also at this point these are old rare motors that only collectors should mess with.

[pcrussell50]

Two more things worth thinking about. Even if you find a Promax 225 or a 225 X or even a run of the mill 200 EFI 2.5 which I believe was last produced smartcraft capable in 2003 you are still talking about 20 year old motors. Important that you have someone with knowledge somewhat close to you to service them. On the 260/280 hi end stuff the guys "who know" are dying off and much harder to find. Also, to throw something else at you (nor really knowing your set up) might also be worth looking at a new 3.4l motor from Merc with warranty if the performance does not call for Promax or X 225 weight or grunt.

good info, thanks.

Thanks in part to S&F I’m getting by quite nicely with a 35 year old motor (1987 carb 2.0/150), so an EFI Promax 225 would be like something shiny and new to me.

Also, unfortunately, weigh is an issue. My 1987 boat needs 1987 weights. Which is why I started off thinking that a nice 2.4/200 would be the way to go. I still think that. But S&F has been the Promax love site for so long, it’s finally rubbing off on me. :-)

-Peter

[whipper]

On year 19 I think haha with out a rebuild with my 7500 rpm 225 promax with 33cc heads. ,, Some how! Oh and runs strong. Id say i lost a tiny bit of compression based on the loaded performance but over all I cant possibly have any complaints what so ever with the the stock EFI promax complete assembly. They are also highly modifiable. There is also a 150. Good link https://www.screamandfly.com/showthr...-150-Promax-SS

[moatorbotin]

How much speed difference would there really be all things being equal save for 200FF vs 225 promax?

no definitive testing yet, I’m chasing an electrical issue.

but, 200efi pushed me a best of 87, and 82-84 most days.

first run with the pro max (engine height and trim not yet dialed in) 90.2

same prop.

I think the pro max will turn a 30, while the 28 was plenty for the 200.

how much more will I get? I dunno, but on my boat I’m gonna guess the pmax gets me 5-7mph? Maybe more? Don’t know yet.

[Greg G]

Probably also have to consider that many of the "Promax" and "X" 225 motors came with Sportmaster's which could be raised up and surfaced to gain speed if you wanted it.

[LakeFever]

Is the stock promax sporty the same build spec as the 260/280 sporties?

[moatorbotin]

Probably also have to consider that many of the "Promax" and "X" 225 motors came with Sportmaster's which could be raised up and surfaced to gain speed if you wanted it.

"could come" - not all came with a sporty, it was an option. *edit* sorry misread your comment, yes, many did come with sportmasters. My understanding was the sporty became on option on the "pro max" series (150, 200, 225) and was not available on the standard EFI motors.

Is the stock promax sporty the same build spec as the 260/280 sporties?

Yes, as far as I know.

For reference. My 200 was bone stock with my sportmaster bolted to it, rubber mounts and all.

225 is on a once piece/280 bass MID with the same sportmaster I used last year on my 200.

Biggest difference I noticed so far is how much less input the boat takes to drive with the 280 (non offshore) style mid with the solid mounts.