XR-6/Mariner Mag III

[K-Dawg]

Is there any upside to a XR-6/Mariner Mag III. What I mean is why don't they just call them a 150? Thats all they are right or is there something to the designation (name). And if there is something special what is it?

[The Big Al]

It was a detuned 200hp with a faster lower unit.
Built back in the day when 150hp was limit on Bass tournament boats.

Carb and tuner change, remove module and ya got ya 60 plus hp!

Al

[K-Dawg]

I have a Mag III a 94 year model. Just wondering what I have. Now I know, what carbs, tuner and module. I am assuming the carbs and tuner could be taken off a 200. What does a module do and can one be found in the same place. And how hard is this to accomplish. Thanks Big AL you have came to my rescue with ever newby question I have posted!!!

[The Big Al]

Easy! Thier is a control module black box, on the back of the engine it's 1inch thick, about 3" x 6".

It's a high idal controller and retards timing when engine gets to 5700rpm holding back power.

Yes 200 carbs and Tuner.

I have both!

Off my XR6 conversion.

Now run EFI.

Can make you a hell of a deal!

[email protected]

Al

[K-Dawg]

What is a "hell of a deal"? I have never seen 5700 rpm as high as I have seen is 5600. This is with the crappy laser II 25 pitch. Do you have a module or can this be purchased from merc, or a fellow scream and flyer?

[The Big Al]

What is a "hell of a deal"? I have never seen 5700 rpm as high as I have seen is 5600. This is with the crappy laser II 25 pitch. Do you have a module or can this be purchased from merc, or a fellow scream and flyer?

You unplug the module, take it off!(you have it now)

Have timing set to 25 degrees wide open.

Carbs are what turn it on! Big time.

215.00 for carbs and tunner, Shipped.

And I take paypal you can pay with credit card , check, debit, it don't mater.

AL

[K-Dawg]

What would be the max rpm I could expect to run and not hurt anything. Or what rpm range are we talkin. Would there be a noticable differance in the seat of the pants and topend. I mean who are we kidding its all about the speed right?

[The Big Al]

No, it's not BS!

It's very very true.

Should jump 6200-6300 rpm, and torgue!

You will feel it, see it, know it.

AL

[K-Dawg]

Is it safe to run the motor at 6300, is it going to come apart after a day on the river turn'in 6300 rpm. Could you turn it 6500? I have been told I could change this stuff before but not how much more power I'd have after the swap. I am sorry I don't have the funds at this time. But As soon as I can I will take them go fast parts of your hands. If you still gott"um in a few weeks. Thanks for the info and I'm sorry I ain't got the cash I feel like this is a bargain I just hope knowone is read'in this post and the stuff don't get sold.

[The Big Al]

that rpm will not hurt it.

AL

[Ron V]

Not all of them have the faster lower unit. The small 4.25" case with 1.78 gears was first made available with the XR4's and Mag II's, and when the motor evolved from the 2.4 to the 2.5 and became the XR6/Mag III, the lower unit followed. But the last few years only the 4.75" case with the 1.87 gears was available. That's how mine is. XR6 was basically just a name for the carbureted 150 at that point. Great running motor, very gutsy and gets excellent gas mileage for a V-6 unless it's on a boat that weighs 2 tons.

[The Big Al]

Ron V! WHat the deal?

1995 Rapid Craft Hurricane with jock itch of the transom
2005 Mercury 150 XR6 - mothballed

Explain! MAN!

[K-Dawg]

Ummm...... we seem to have a difference of opinion. If i'm reading this correctly.

[Ron V]

K-Dawg, you might have the 4.25" case, you might have the 4.75" case. The older ones had the smaller case, then it was dropped at some point. Do you know the model year or model number? Someone here should be able to tell you for sure. My brochure collection is at my dad's house and I quit collecting the brochures before the changeover, so I can't help you. You could measure the diameter of the case, or try a large hub prop and see if it fits. If it fits, you've got the 4.75" diameter 1.87:1 case. If it doesn't, you've got the 4.25" diameter 1.78:1 case.

Al - I thought you had seen my earlier post on the boat, but I will post more on this later tonight since I've been meaning to put some pics up of the stand that I've got the motor on. Some guys were asking about stands awhile back and I've been meaning to put it up.

[mach351]

Ive been turning my '95 Xr6 7100rpm for the last three years without a problem! Junk the carbs and the tuner like Al says, rip the module off and give the 'ole girl a little shaving on the heads for some compression! I took .080" and run a 1.0mm head gasket. My opinoin is thats its "almost" a 200 now. The only difference between the two is the compression releif in the exhuast port - not really desirable for performance aplications - but like i said mines been doin fine for a long time now... (knock knock knock):D

[K-Dawg]

I have the large gear case on my ron. In june I ate a gearset at the glenn on lake george. And when i looked up the model no. on parts express it listed both but when I run the numbers on the gearset that came out of it, it turned out to be 1.87 gear ratio. So I purchased a new gearset and replaced them no problems since. Although it was a 1 month learning curve to install them correctly. All I wanted to know about was the mag III designation and if it was possible to pump up the power cheap. I owned a xr-4 prior to this motor and it had the small case. My mag III is a 1994 year model. the xr-4 was a 1987 year model.

[MODXR6]

Did the same upgrades as AL, + a lil more
I was pushin a 1450 lb dry weight skeeter hull to 6600 rpm all day long. Motor had more to give but I was limited by the hull ;-)
Dat's why I got a ally now ;-)

[K-Dawg]

What is a promax 150 ss? Is it a xr-6 you modified and if so what did you do to tha motor?

[MODXR6]

Nope not quite the same as an XR6 although i is a 2.5
Basically same mota as a 225 ProMax with different porting

oh & about 75 hp short ;-)

[Reese]

modxr6...

Did you happen to do any porting work on you xr6. I currently have an xr4 that I plan on modifying over the winter. Not sure about the port heights on the xr6 but mine are 1.65 exh and 2.20 intake.

What else did you do and what was the biggest improvement?

[The Big Al]

Reese the bolt on changes would be the linit I would go, and cutting the heads.

All the rest becomes a pain in the ass, and it will die! BOOM!

AL

[Reese]

I was actually thinking of only doing very mild porting. The top part of stock sleeves are slightly lower then the port roofs. I was just going to blend them in and polish but not enlarge the exhaust port.

[MODXR6]

smoked 2 pistons when it was still under warranty so while it was in the shop had the block sent to Roberie for porting to 200 specs. Changed carbs to WH20's w/ large jets(can't remember size) to keep from running lean. Cut heads to 35cc. Had already done all the other bolt on mods before that. Mota never idled very good but was worse after carb change. Bored mid above waterline & idle was great after that. Mota ran like a spotted azz ape till I sold the boat. I had the small case w/ 1.78/1 gears.