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150 Mariner magnum 2 vs 150. whats the diffrence????

roadkill636

Member
I picked up a 1988 Mariner Magnum ll it is a 2.4L and im wanting to know what tecnically is the "Magnum" part of it? I see some of the Merc - Mariner 150 in both 2.0 and some in 2.4. So whats this Magnum ll upgrade diffrence?lb
 
That's the difference, 150 mag I is 2.0, mag II is 2.4, mag 3 is 2.5

Same differance in mercury between XR2, XR4 and XR6
 
Im meaning. What is the diffrence between a motor that is a plain 150 and a 150 magnum of the same displacement of the same year? Is it a upgrade from the plain 150? More hp but de tuned down to 150.
Sort of like a Ford F150 xl compared to a Ford F150 Lariet package.

What is the Magnum?
 
No difference from what I've been told, it just looks cool, most of the mariners say magnum on them, even the 10 hp.

It's like people stating in for sale adds that they have a Mercury "Black Max" like it's something special, doesn't mean squat.

The Super Magnum is a different story, it's a hot rod motor with a higher RPM range.

I'm a big fan of these old motors, mine is a 87 220 hp mariner magnum EFI, in 5 years of running every weekend in the summer I've replaced one rectifier, that's it, runs strong every time.
 
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Magnum III was fuel injected as far as I know, I have a 88 mariner brochure at the lake so I can take a pic of both motors specs and post them for comparison if you want, will be a few weeks before I get up there tho.
 
Mag II is just a mercury XR4 with a grey cowl. 2.4 liter, 150 HP carbureted 16 amp charging system. Vertical 5 petal reed cages. The Mag III was the same motor as the XR6. 2.5 liter with a 40 amp charging system. It is/was carbureted as well. Crappy small bore carbs.
 
Getting the heads cut to 33 cc and cutting the tunner to 7" & 8" for a bit more ponies. Also it has WH 41 carbs on it. Are they decent for top end?
 
If its a 2.4 liter you can comfortably go down to 30 CC on premium gas. Carb series doesnt matter as long as its jetted right.
 
I got a square bell tuner from a 200 that is almost new that would work better than cutting yours.
 
Dont really know as I did the tuner, heads and reeds with ported reed cages on my old xr2 but after that it made a big difference up top. It lost a little on bottom end but I think I saw around 2 mph in a heavy glastron and it pulled hard as hell from mid range on up to 6400. If I would have changed the prop it might have done more.
 
Had a chance to look at my brochure and difference between magnum 150 or just plain 150.

150 is 2.0 and 150 magnum is 2.4

Regular 150 is 2:00-1 gear case and magnum is 1:87-1

That's about it according to brochure.
 
Had a chance to look at my brochure and difference between magnum 150 or just plain 150.

150 is 2.0 and 150 magnum is 2.4

Regular 150 is 2:00-1 gear case and magnum is 1:87-1

That's about it according to brochure.



Thank you. And mine has had the LU replaced with the larger 4 3/4" 2-1 instead of the smaller 4 1/4" lu. Longer lasting when surfacing prop.
 
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