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

[Wizard]

You think if you modify your motor they are not going to know?

If winning tourneys is your game then leave it stock or buy a faster boat.

[Mesabooger]

Pretty sure they wont know, never seen them take the cowl off of a motor or put one on a dyno there swifty. I dont think they would say anything unless you ran the exhaust above the water or had a NOS bottle strapped to the top of the cowl? It's not nascar. But thanks for those great words of advice. I'm not trying to be faster than those other guys I just want to be able to run with them. When you're running against those 250 Pro XS's, a stock 150 doesnt stand much of a chance.

[Wizard]

You do ANYTHING with your tuner and they will know. Especially on the 2.4's. Cut it, replace it, no matter. The engine will sound very very different. You can't believe how restrictive the stock tuners are. And heads would be worthless without the tuner.

As soon as you start it while waiting for blastoff someones gonna say hey listen to mesaboogers motor. What did you do to it? Games over dude.

Been there, done that!

[vmax80096]

Wizard, what tuner would you go with, my brother has an xr4 and would like more hp out of it, saw one article where they used a tuner from a 2.4 bridgeport....why not use one out of a 200 2.5...his motor is a 2.5 150hp?

[Mesabooger]

Wizard, If you dont have any real technical advice to give I'd appreciate you just not commenting. To the guy above asking about which tuner,...I'm a newb to this whole thing so I couldnt give you any advice about that. These guys on here like Al can help you out.

[The Big Al]

As for as tunner.
The only thing they can tell and (they trully don't give a crap) is if you take the bucket out.
Tuner change does not change the sound!

Removing the bucket and (or) drilling the mid section changes the sound.

And it do sound good!!!

[tlwjkw]

Al, we finally agree on sumin'. As long as tha can is in and tha lower unit is buried tha noise ain't gonna change. Tuner change don't change nothin' on sound or performance unless ya do some other stuff as well (like he says, removin' tha can, exhaust ports, drillin' down housing, surfacin' tha lower unit and etc). Just changin' tuner is "snake oil" unless ya do a lot of other ****. It don't do anything unless ya buildin' a "stem winder" motor thats gonna get on up on tha high side of rpm bracket. Best thing ya can do for tha XR4 is cuttin' tha heads a hundred thousands ta start then go from there...............T

BTW, ya need ta get your "set up",(includin' your prop) right and to its max before ya start doin' anything. Then ya do one thang at a time (spendin' money) and moniter tha results.

[vmax80096]

thanks for the input...not sure want to cut the heads that much because we ski lots and use 87 gas...on a farm thus purple and it only comes in 87. Just thought that changing the tuner would be worth 10hp. While I'm on, is there a 1" manifold spacer that works also on a carb model..that is what the xr4 is? How much could the heads be cut and still run 87 or is that not possible?

[The Big Al]

Al, we finally agree on sumin'. As long as tha can is in and tha lower unit is buried tha noise ain't gonna change. Tuner change don't change nothin' on sound or performance unless ya do some other stuff as well (like he says, removin' tha can, exhaust ports, drillin' down housing, surfacin' tha lower .

ALMOST!!!

Any of the 2.4 or 2.5 tuners are performance reducer tuners, they are long, and very small in size designed to reduce HP. They go from the exh adapter all the way to the bottom of the bucket. The 2.4 & 2.5 could make more than 150hp easy, they used tuner & very small carbs & timing module to reduce power. On EFI they used tuner, ECU curve and timing module to reduce power.

On the carb models all you had to do was change or disconnect the timing module and you instantly gained 300-500 RPM.

When the engine reached 56-5800rpm it would retard the timing acting like a rev limiter.

Al

[tlwjkw]

Since ya got a multi-task boat I would just leave it alone as long as its doin' what its supposed to. If your gonna stay with low octane no need in doin' any cuttin'. Anything else ya do to that motor ta make more horsepower is gonna take away from your bottom end torque which is gonna make tha little motor work harder, burn more gas and wear out quicker. If you want more power on a ski boat, buy a bigger STOCK motor. Thats JMO n don't give a **** what Al says cause he just likes ta hear his self rattle ...........T

[T-REX]

Any of the 2.4 or 2.5 tuners are performance reducer tuners,

Sorry but I kan't pass this up witout thro'in my 2 centz in yher!!!!

Tha 200HP 2.4 tuner iz a good tuner for all round performance on a 2.0/2.4/2.5!!!!.....it iz NOT long and restrictive, but ov sorta short and bell stature...it will fit in tha can, and also helps bottom by not stick'in so deep in tha water while idle'in...

swapp'in ANY tuner for a 200 2.4 tuner iz a NO LOOSE situation!!!!.....In sum cases it may not make enuff differnce to notice, but I have never put one on that HURT performance over tha other's.......an I have tried them all!!

Hell, my collection may be gitt'in az big az Raceman'z!!!

[tlwjkw]

Hell Rex, ya know ya ain't gonna live long enough ta have any collections of anythang get anywhere close ta Raceman'z. Well maybe tha used stuff

..............T

[302w]

I know you are wanting to get to 70 but the only way you are going to see 70 is to put a 225 on it and if you did that, you would not be allowed to fish the tournements. The Z-19's can barely break 70 with a 225. I would leave it alone and find a big block 200 and work from there.

[The Big Al]

ALMOST!!!

Any of the 2.4 or 2.5 tuners are performance reducer tuners, they are long, and very small in size designed to reduce HP. They go from the exh adapter all the way to the bottom of the bucket. The 2.4 & 2.5 could make more than 150hp easy, they used tuner & very small carbs & timing module to reduce power. On EFI they used tuner, ECU curve and timing module to reduce power.

On the carb models all you had to do was change or disconnect the timing module and you instantly gained 300-500 RPM.

When the engine reached 56-5800rpm it would retard the timing acting like a rev limiter.

Al

Im was speeking of the 150hp engines IE: XR4 XR6

[The Big Al]

The 150Hp tuner is part number 12834A2

The 200hp tuner is 419424