How can I get 200 hp from my 150 EFI Merc?

[The Big Al]

Thats JMO n don't give a **** what Al says cause he just likes ta hear his self rattle ...........T

You are one of the very reasons I don't post on S&F as much when helping people.
It's the (I don't know **** advice makers like you) who always have there chest poked out like a walking encyclopedia.

The guy wants to take his 150 and see what it takes to make more HP! He can achieve a 200hp engine just by changing the very parts that are different between them.
I'm not saying he can get 70mph. But he can get more HP just by changing bolt on parts and maybe a little extra.

He has 2 variables HP and setup and does have a lot of ability to capitalize on these changes.
Setup:
Jack plate
Prop
Nose cone; but not mandatory
Engine:
Reeds
ECU reprogrammed
Tuner change (it is ****ing restrictive)
And can cut heads to a safe 34cc and will have to run premium fuel.

And these changes WILL NOT REDUCE LOW END POWER OR REDUCE TORQUE!

It will improve it!

He has set a goal.
A very achievable goal!

I'm done!

[Mesabooger]

Hey Al, and everyone else for that matter. I appreciate all the advice that is given on here. Dont let a bunch of naysayers keep you from giving advice. There are ppl on every board that just like to be the thorn. F'em and ignore'em. Anyway, I'm going to take your advice and work on my set-up, then do the other things you mentioned. I'll report my results. I'm looking for a set of heads for my motor (99' 150hp EFI..post is long thought you might've forgot) if anyone knows where a good deal is. Thanks

[Mesabooger]

Okay, heads have been obtained thanks to Big Al...........

[macutty]

There are other reasons to want to do this mod....like insurance.

I'm having the same delima of try to get real power out of a 150hp rated motor so I can keep my full liability coverage.

[pjbrownva]

You are one of the very reasons I don't post on S&F as much when helping people.
It's the (I don't know **** advice makers like you) who always have there chest poked out like a walking encyclopedia.

The guy wants to take his 150 and see what it takes to make more HP! He can achieve a 200hp engine just by changing the very parts that are different between them.
I'm not saying he can get 70mph. But he can get more HP just by changing bolt on parts and maybe a little extra.

He has 2 variables HP and setup and does have a lot of ability to capitalize on these changes.
Setup:
Jack plate
Prop
Nose cone; but not mandatory
Engine:
Reeds
ECU reprogrammed
Tuner change (it is ****ing restrictive)
And can cut heads to a safe 34cc and will have to run premium fuel.

And these changes WILL NOT REDUCE LOW END POWER OR REDUCE TORQUE!

It will improve it!

He has set a goal.
A very achievable goal!

I'm done!

Hey Big Al...

It might be 13 years later, but thank's for the advice!

I'm getting close to pullin' the trigger on a new-to-me bass boat with a 150 XRi (2.5L), and if I get it, I'll follow your advice... that is 200 Tuner (I've got one!), reeds .... gotta price 'em out... plus I'll ask and see if I can still see good improvement without changing the reeds... I'm cheap! Remove timing adjustment black box, and get a 200 ECU, aftermarket ECU, or have mine reflashed (I think I'd look on S&F to see if anyone already has a 200 ECU or a reflashed one they wanna sell)....

Thanks for the road map! Now... to figure out where to hide boat #2 so that da boss (read wife) won't find out about it! (hehe!)

[Capt.Insane-o]

The block has to be ported or re sleeved to get anywhere near 200 hp. It's easiest to drop in 225 promax sleeves. Putting a 200 ecu on a 150 will just be a smokey blubbering mess.

[pjbrownva]

The block has to be ported or re sleeved to get anywhere near 200 hp. It's easiest to drop in 225 promax sleeves. Putting a 200 ecu on a 150 will just be a smokey blubbering mess.

I didn't know that... but this is all new to me. Hopefully I won't be doing any rebuilding, and that would make it a moot point!

None-the-less, thank you for the information. It sounds like if I want a 200 or better, it might be best to get a 200 power head. I've never put in a crank and pistons, etc, and that's probably a little above my skill level. Although, I guess if I could do it in 12 hours or so, I wouldn't mind putting in the work.

[pjbrownva]

Actually, on second thought, it's better to say that I don't know what's involved in putting a sleeve into a block.... maybe it's not too bad, and not that expensive. I guess I'll cross that bridge if and when I come to it. :-)

[tlwjkw]

i tried ta tell ya it wasn't gonna happen way back then.. bolt on's ona XR6/EFI 2.5 block will never ever get ya what ya lookin' for... jus add compression to it for now.. that will get ya about as far along as it gets... sleeves/installed gonna be around minimum 150 bucks a hole ina bare block.. save ya money and find a good 200/225 rotatin' assembly and go from there.........

[TEXAS20225]

it never changes Tommy i cannot tell you how many"out board" mechanics spew all that BS on change the tuner and ecu and walaa u gotta 200 efi . After over 400 rebuilt 200 efi's and not counting anything else ive rebuild in the last almost 20 years it just aint so it has to have 200 intake porting and 200 exhaust porting along with the ecu the tuner is a bull shaveek story its worth ziltch 150heads are better then the 200 it will have more compression on a 200 ported block you just cannot get there with out cutting on the ports or change the sleeves out you can turn a 150 in to a 200 that way .And to say you can without it is a "not true" (not counting small exhaust chest in 150 block)


PS sleeve change out is not for the unknowing it is changed by cutting old sleeve out and boring the register to what it takes to clean it up maybe .020 thousandths then heating block out to 450 degrees for a while couple hours maybe less and slide it in then bore and deck them off take lot of work and machinery so cheapest way is buy it already built

[pjbrownva]

Thank you, all. Today at dinner, the wife gave the thumbs up on the new boat / mota for me. :-) So now I'll contact the friend of a friend, arrange to see it, and take it home if I like it! Sounds like I'll stick with the 150 Xri Stock for now, and be happy to have 2.5L. If I can get my hands on an extra set of heads, I might have those cut and put on the 2.0L (maybe)... but I know you need high octane gas, so it's probably best to listen to what several people said, which is save my $$$, and look for a good 200 HP 2.5L power head to pop on my 2.0L. Then, I can use it with the 200 exhaust plate and 200 tuner that I already have... plus the proper ECU (as needed) if it's fuel inject, or the 200 carbs that I already have (minus the high speed jets, which I'd have to acquire).

Thank you for the info. I definitely WON'T be doing any sleeves or porting work. I don't have the shop, the tools or the experience!

Cheers!

[tlwjkw]

now ya thinkin' straight............

Bobby, ya absolutely right bud!............

[Merc 2.5]

U will notice a pretty big difference between the 2.0 150 and the 2.5 150 tho. It will have alot better torque. Also if u get tired of 150. Put it up here for sale and turn around and get that 2.5 200. Your still headed in rite direction. Good luck. Dont get to excited and check boat out real real good