Mercury 2.5 and 3.0 swap thoughts

[DieselDood]

So I spend way to much time driving. This leads to my mind wandering. When my mind wanders I think of things... and well things like this come to mind.


I currently have a 2.5L 200hp EFI on my 1998 Triton TR21. 95% of these boats came with a 225hp which is a 3.0. So I'm underpowered and I know it. Sooner or later I plan to get a rebuildable 3.0 and swap them out.


A friend of mine hit something and the lower unit left the chat at 65mph, also breaking the leg. (yes he went on the wild spinny, wet ride! But still sacked up 16lbs for the day and made the regional team)

The shop told the insurance company they think the bottom of the crank is probably damaged, possibly even bent the crank, so the motor was totaled and he now has a new/used motor.


Soooo.....
That got me thinking, and Google did not help, so here I am to ask the experts.

Will the Leg and lower unit from a 2.5 bolt up to the 3.0?
Could I pull the 2.5 powerhead and covers, seal it the motor up, and put it on the shelf. Then drop the 3.0 on with covers in it's place? Kind of like the bellhousing on a vehicle, a 350 will bolt in where a 305 was very easily. At least that is my thoughts... my 2.5 uses the bigger lower gear housing even. Are the splines the same? I find some contradicting posts on that, so I'm not sure there. Again Google really didn't help, it actually muddied the water more for me.

Even if I have to replace the crankshaft on his old motor, it was well cared for, and ran great. Swapping out the crank and putting the powerhead on my leg/lower could happen in a weekend. Although, really I'd probably do it right and more than likely (hopefully, be able to) hone the cylinders and put new rings in it, just to make sure everything is good. (send injectors in to get checked....etc... its apart... do it right)

IF I can get it for the right price, I don't mind putting in the work. Then I know what I have. I potentially could take what is currently an anchor and turn it into a good solid running motor. At least that's my thinking.

I do know that the controls/wiring may be different, but when I do make the move from the 200 to a 225, I would need that anyway, so no harm no foul there. It would be really slick if it didn't even need that changed... but that's not really a huge worry at the moment. The physical motors are where I'm at.


So... back to the real question at hand... if I can get his old motor for cheap... can I drop his old 225 3.0 (I believe 03) onto my 98 200 2.5 Leg/Lower and swap the upper and lower covers?

[OnPad]

Nope.

[David - WI]

You could get 225 - 300hp out of the 2.5 if you eally think you're underpowered. A 225 Pro Max is probably 240hp, and you could get that out of your current motor.

[derekfl]

The bottom of the 3.0 is completely different from the 2.5. Just go on Amazon and look at the powerhead mount gaskets to see the diff.

[rock]

sent pm

Rock

[DieselDood]

You could get 225 - 300hp out of the 2.5 if you eally think you're underpowered. A 225 Pro Max is probably 240hp, and you could get that out of your current motor.

As fun as that would be... I do fish tourneys with it and the rules say I can't play like that. BUT... I can put a bigger non-modified motor on it.... ugh... stupid... but yeah, the rules.

[Aaronhl]

Nope.

My thoughts exactly however the question is can Chaz do it or has done it haha!!

[JPEROG]

Scott Porta spent the time and money to produce an exhaust plate that adapts a 3L power head onto a 2.5 midsection. He has a ton invested in them and I have no idea what he would charge for it but it has been done.

Joe

[Aaronhl]

Scott Porta spent the time and money to produce an exhaust plate that adapts a 3L power head onto a 2.5 midsection. He has a ton invested in them and I have no idea what he would charge for it but it has been done.

Joe

I messaged Scott on Facebook if he makes them and this is what he said

"I do, but it is not profitable for me to make them."

"The last ones I had made cost me 5 k each just to mill and the guy who did them for me doesn’t want to make them anymore. I spent 2.5 years on the design work and learning cad. I only got three made, and I m using them."

I am asking him for pictures...

[DieselDood]

Wow! That's crazy! 5K oof. A guy can buy a blown up 3.0 for that. I don't understand why that would be worth doing at all?

[johnmiffco]

just a thought,,,,if u fish tornaments go find u a 250xb motor
its basically a 300pm powerhead on a bass mid
merc made em for the tournament people to be legal
and yes u can make more power out of your 2.5
but the torque difference in the 3.0 helps alot on a bigger hull