newbie to the v6 mercs...

[Part-Time]

I just picked up 3 parts engines, enough to build 2 good ones... but 2 of them are basket cases and I'm trying to figure out what's what?
First off, can someone explain to me the difference from XR1/XR2 and regular engines?
The first engine is complete, not running, but not seized.
It's a 200 extra long shaft (25" mid) with a one piece cowl. The numbers on the tag on the transom clamp are all erased.
http://img845.imageshack.us/img845/88/39670610151868638080487.jpg
The other 2 are 20" mids.
numbers are A933604 and 0D043980
http://img405.imageshack.us/img405/2992/31879810151868637920487.jpg
http://img818.imageshack.us/img818/2544/25093810151868637950487.jpg
And the cowls
http://img696.imageshack.us/img696/4999/53970210151868637880487.jpg
I'd like to have an idea of what year they are and what were the major differences.
Oh yeah, and are these 2.5 liter engines?
Thanks in advance for any info.
PT

[Part-Time]

I didn't think these motors were that rare that nobody knew anything about them...

[luckybuff]

I didn't think these motors were that rare that nobody knew anything about them...l

The one on the right (red,gray) should be a 1987, 2.4 litre. Mine is a 175hp screemer with carbs. Good mota. Stock cylinders walls should be chrome unless it has been re-sleeved. Do not hone chrome cylinders.

luckybuff

[ncst8er]

It would help if you had pics with the cowling removed, but I would guess that they are not 2.5's. Probably 2.4's.

[ncst8er]

According to Mercury Marine, the second serial no. is:
MARINER 2.4L MAGNUM II 150MG2 ELPTO
Unfortunately, if there's been swapping of powerheads, etc, the serial no. may not tell you much.

[Part-Time]

this is the block and one of the sets of heads that came with the 150 and 175.
the other set is similar but different waterjacket covers.
http://img526.imageshack.us/img526/216/39686610151873506240487.jpg

starboard side of the 200
http://img687.imageshack.us/img687/9035/41744610151873506135487.jpg

and port side
http://img215.imageshack.us/img215/9518/48069710151873506130487.jpg

[TEXAS20225]

the bare block is first generation Merc v6 it came on the Mayflower it aint much punkin for rebuild the head bolts attached to the sleeves cause all kinds of trouble second motor if its a 200 is most likely a 2.4 but it could be a 2.5 does it have water cooled regulator breather looks like a 200 2.4 pull the heads if its 33/8 answer is there

[Ron V]

The 1750 with the blue stripes is only a 2.0 litre if I'm not mistaken. It looks like one of the early ones. The only 2.4s with blue stripes that I know of were the 200s and 225s and those came later when the stripes were just horizontal lines and didn't drop down in the back. Our Merc catalog collection is at my dad's house some I'm going from memory on how they all looked. Attached is the photo from the catalog when the 2.0 175 was introduced.

There was no XR1. You probably mean XRi, which was the fuel injected version which debuted with the 2.4 I believe. The XR2 was the "hot" bass boat version of the 2.0 litre 150 that came out in '84 or '85.

[TEXAS20225]

if the numbers you have posted came off the clamp bracket they could be any thing if you trying to tell what they are from the cowling that could prove futile i have seen so many motor midsection combos it unbelievable and i swap them around my self i just built a 1998 175 HP carb block added 150 EFI system then it then put it all on a 1993 xr6 down housing with a 1.78 small bullet case and a 2.5 Merc260 cowling so there you go, i put all that on a very clean 1977 Powercat that had the original 1750 still on it

[davemvegas]

your 200 looks like it is a 2.5 it is not clear in pics. look at the plate the coils are mounted to.if there is 1 voltage regulator behind it that that is bolted to exhaust plate with gasket between reg and exh plate motor is 1991.that water cooled reg was a 1 year bad idea.the good thing if its a 91 motor is it will have pumper carbs and 7 pedal horizonal reeds.i have read good and bad reviews on that year block because it has idle relief slots in the sleeves above the exhaust ports.the theory behind merc doing this was to bleed off some compression at lower rpms when cylinder pressure and cyl temps spike under load.heavy boat or heavily loaded boat working to get on plane can have pre ingnition and burn piston.by bleeding off a little cyl pressure added a little cushion if your gas lost some octane while being stored or just was a less than recomended.once motor revs up above 3500rpms the releif slots dont have time to bleed off any compression.so motor loses a little low end torque.i had one recently and it ran as good as any non relief motor i have had.

[Part-Time]

Can anybody tell me what the bore and stroke were on the 2.0, 2.4 and 2.5
I just checked the compression on the 200 tonight, 115-120psi on the top 4 and 60-70 psi on the bottom 2 holes...
I'm wondering if the pistons from the 150 or 175 will fit in the 200.
Also a link to how to delete the oil injection and other things that should be removed or modified on the 200 would be great!
Thanks for all the help guys.
PT


And yes Dave, the voltage regulator is bolted to the exhaust plate.

[davemvegas]

2.5 has a larger bore size.remove oil tank and pump.pump is on port side. remove the 2 bolts and pump will slide out easily.plug fuel pump where oil line attaches.get plastic block off plug from merc parts supplier to bolt in place of oil pump.disconnect hose that runs from onboard oil tank to starboard check valve on the sind of block.remove valve and plug hole with pipe plug.someone else here will have to help with removing alarm box or tell you the wires to jump.but probably a long shot at best you will get this motor up and running any time soon.

[Part-Time]

I pulled the heads off of the 200 tonight.
It's a 2.4
and it looks like I'll be looking for a 2.5 block to replace it.
the two bottom jugs have some scoring (looks like broken rings) and all 6 have some pitting... and they're chromed jugs :nonod: