1987 150 XR2 vs 1977 175 Black Max

[chan93lx50]

How much power would I lose going from a 1987 150 xr2 to a 1977 175 Black Max? My 150 merc is blown and have a deal on a 1977 175 merc. I would be using the same prop just curious if I would see much power difference.

Thanks

 

[Bondo]

Re: 1987 150 XR2 vs 1977 175 Black Max

Ayuh,... I see a Gain of 25hp,.... Not a Loss in hp....
Even if the point of rating changed during those 10 years,...(powerhead, vs. prop)
You'll be Even or Ahead in hp...

 

[Faztbullet]

Re: 1987 150 XR2 vs 1977 175 Black Max

As in earlier post , you will see about the same HP. I would not "de-rig" the 1987 off the boat as the 77 uses a different wiring harness and trim system. This is how I would address this:
1) Pull 1987 power head and adapter plate
2) Pull 1977 powerhead and adapter plate
3) Install 1977 powerhead and plate on 1987 midsection
4) Swap wiring harness from 87 to 77 so it will "plug in"
5) Remove the advance/idle stablizer from the 77 model
6) Install the carbs and enrichner off the 87 and dump the "butterfly" choke

 

[chan93lx50]

Re: 1987 150 XR2 vs 1977 175 Black Max

Hmmmmm Might be too much work for the price, how big of a Difference from an 84 150 merc would it be from my 87

 

[j_martin]

Re: 1987 150 XR2 vs 1977 175 Black Max

The 77 150 is a 2.0 L. The XR2 is the same engine. The big difference is the smaller prop diameter and slightly higher gear ratio. Actual out of the crate HP is about 160.

I wouldn't change engines or power heads, but I might tune up the XR2 a bit. If it's in good mechanical shape you can ditch the advance module, time it at 23 degrees, shave the heads to get 145 lbs compression, dial in the carbs, prop it for 6 grand, and have one kick-*** engine.

Even stock it ain't no kids toy.

John

 

[chan93lx50]

Re: 1987 150 XR2 vs 1977 175 Black Max

The XR2 piston #1 is melted, so I have been looking for a replacement motor. Damn it ran hard sad to see it go. Just not sure how much jack it would take to get her running again. I live in Iowa and really do not have any leads on any trust worthy shops around here.

 

[Mercs and such]

Re: 1987 150 XR2 vs 1977 175 Black Max

hi, Go for the 175. check the conditions especially if your going from a 87 to a 77. Looks can be deceiving especially on older outboards.

I personally love the XR2's. good motors and good looks. If you have the time, patience, and money, you can have her purring again. you would have to pull the powerhead, disassemble completely, bore out the cylinder and put in a .20 overbore piston depending on level of cylinder damage. put it all back together.

good luck! let me know what you decided on!!

 

[sschefer]

Re: 1987 150 XR2 vs 1977 175 Black Max

The XR2 piston #1 is melted, so I have been looking for a replacement motor. Damn it ran hard sad to see it go. Just not sure how much jack it would take to get her running again. I live in Iowa and really do not have any leads on any trust worthy shops around here.

How's your mechanical skills? It's a motor that's worth fixing for sure. These are really simple engines. Once you get past the fear the rest is easy.

 

[achris]

Re: 1987 150 XR2 vs 1977 175 Black Max

As in earlier post , you will see about the same HP. I would not "de-rig" the 1987 off the boat as the 77 uses a different wiring harness and trim system. This is how I would address this:
1) Pull 1987 power head and adapter plate
2) Pull 1977 powerhead and adapter plate
3) Install 1977 powerhead and plate on 1987 midsection
4) Swap wiring harness from 87 to 77 so it will "plug in"
5) Remove the advance/idle stablizer from the 77 model
6) Install the carbs and enrichner off the 87 and dump the "butterfly" choke

And this is precisely how we end up with "FrankenMercs". Engines that only the person who did the bastardization can work on. Pity the next poor sod who has to own/maintain it.

Chris......

 

[Faztbullet]

Re: 1987 150 XR2 vs 1977 175 Black Max

This wouldnt be "bastardization" just a modification to a 77 175 V-6, no different than your signature, 1972 model boat with 06 motor and drive.. just a modification

 

[Dukedog]

Re: 1987 150 XR2 vs 1977 175 Black Max

Hmmmmm Might be too much work for the price, how big of a Difference from an 84 150 merc would it be from my 87

?????
Is a different deal from what your sayin' 'bout tha '77 ta '87?
If they are both ('84, '87) "plain jane" 150's there won't be any difference..............

 

[achris]

Re: 1987 150 XR2 vs 1977 175 Black Max

This wouldnt be "bastardization" just a modification to a 77 175 V-6, no different than your signature, 1972 model boat with 06 motor and drive.. just a modification

Very different to my boat... My engine is as it came out of the factory, all of it....

In the above 'mod' you'd have a midsection indicating one serial number and the powerhead showing a different serial number.... If that isn't bastardization, what is?

 

[Dukedog]

Re: 1987 150 XR2 vs 1977 175 Black Max

Ya'll gettin' a little off track. "bastardization" don't seem ta be tha ? here. He asked a ? and got it answered. If thats what he wants ta do then let him get after it. He's at least got tha information and can make tha decision............JMO

 

[j_martin]

Re: 1987 150 XR2 vs 1977 175 Black Max

Odds are good that the 1977 175 block and the xr2 block are exactly the same. Should be an easy transfer.

If it has a steel liner, it can be easily bored and one oversized piston fitted. Even if it doesn't you can get it bored and one steel liner inserted. Just be sure the rings on that one piston are right for the sleeve material.

What made the piston pop? Figure that out before you swap a bunch of parts around or you might just immediately grenade your handywork. Yer looking for double firing spark, plugged carburetor, plugged cooling ports in a head, lost ring pin, etc.

About the frankenmerc bit. A lot of Mercury engines are pretty freaky right off the shelf, like 2.5l blocks bored and sleeved to 2.4l, various carbs, top and bottom guided rods, etc. With reasonable study and care, you can usually mix up parts successfully.

hope it helps
john

 

[86 century]

Re: 1987 150 XR2 vs 1977 175 Black Max

As for the swapping stuff around. I have one now that is driving me crazy. Was told it was a '81 200hp welch plug # 5976270 mount plate # 4869018 with WH 13 carbs. Can you tell me what this thing is those numbers fit 175-225 from '78-'82.

 

[Faztbullet]

Re: 1987 150 XR2 vs 1977 175 Black Max

Look on the heads and it will be cast in them the bore bore size,3-1/8 =2.0 or 3-3/8 = 2.4. This is not 100% as hotrodders use the 2.0 head on 2.4 engines .Also look on side of the block as it will have a assembly date and older ones had hp stamped into flange. 2 was a 200, 5 was a 150 and 7 was a 175. Wh-13 carbs fall in the range of a 1976-81 175 hp.

 

[achris]

Re: 1987 150 XR2 vs 1977 175 Black Max

As for the swapping stuff around. I have one now that is driving me crazy. Was told it was a '81 200hp welch plug # 5976270 mount plate # 4869018 with WH 13 carbs. Can you tell me what this thing is those numbers fit 175-225 from '78-'82.

Q.E.D......



OK... 5976270 shows up as a 225hp, 1980

But you should be starting your own thread....

Chris.

 

[Dukedog]

Re: 1987 150 XR2 vs 1977 175 Black Max

5 petal or 7 petal? My stuff shows a possible '81 200 (usa) but not with
wh13's. Tha 225's will have 225 embossed somewhere on tha block..........None of those came with wh13's that I know of.....

 

[86 century]

Re: 1987 150 XR2 vs 1977 175 Black Max

Thanks for the info. I makes my point on swapping stuff around.

 

[chan93lx50]

Re: 1987 150 XR2 vs 1977 175 Black Max

How's your mechanical skills? It's a motor that's worth fixing for sure. These are really simple engines. Once you get past the fear the rest is easy.

My mechanical skills I like to think are pretty good, I tore a 97 LT1 motor down to the short block and replaced the short block with a crate block. Things get hairy for my when I start talking changing the bore, swapping pistons, and such. I have never done block work per say.

If someone is interested in holding my hand over the internet swaping contact information and walking my way through the rebuild that would be great. Looking over my SELOC repair manual I see no problem getting the motor torn down to the powerhead, Its from there I am clueless