2.0L Merc history and nomeclature?

[pcrussell50]

So I have this overheated 2.0L 150 that I've been posting other threads about a strategy for brining back to life from an overheat in the driveway. I _think_ it's an '86, but I don't know how to tell. The serial number is: 0A970455

I keep my eyes open in case I spot a replacement powerhead for a good deal. Sometimes I see XR2 and XR4 and I have no idea what they mean. I think I need a little schooling in these 2.0L, mid-80's Mercs and their history and what xr2 and xr4 mean. anything else cool or important this 'rude guy needs to know about these mercs?

what year my motor is, (based on the serial number), what year powerheads bolt on. Are these good durable motors? I basically got my overheated one free with a boat I bought. I've been a v4 crossflow guy since I got into boating four years ago. Mercs are new to me, but this one is growing in interest to me.

thx
-peter

[BUSHWACKER]

Use the search in upper right put in cherry red 2.0 look for TRex's info. He's the 2.0 guru
But BEWARE It may take ya a few days to larn ta reed hiz rittin dat he rote it in. LOL
Also his area is still not all better from the hard hit from the storm/water in La so he may not respond right away

[tlwjkw]

I _think_ it's an '86, but I don't know how to tell. The serial number is: 0A970455
-peter

Actual "build" date is stamped on tha block. Bottom of number two where tha block halves bolt together. Kinda behind tha advance timing arm. 1/8" numbers. m/d/y

[Sonik]

Yours looks like an '86 or 87' to me based on the serial. The 2.0 liters are great little motors....at least from my experience. The XR2's (fishing motors) are vertical front 1/2 2.0 liters. There was also an XR2 racing 2.0 that was sold in europe and later in the states.....big difference between the 2...just sayin'...The XR4's are 2.4 liters which also had vertical fronts with a smattering of horizontal front 1/2's I've heard. The horizontal is the more desirable reed cage orientation as they provide a better path and have more performance potential. The XR6 is a horizontal front 2.5 liter motor.

The 2.0 liter steel sleeves are quite a bit thicker than the 2.4/2.5 which contributes to its increased weight (more than a 2.4 if you believe it). What they lack though, is bottom end torque when compared to the bigger displacement motors. The XR2's had a std diameter 2:1 case on them originally, the XR4 had both the small and std bullet gearcases (not sure if the XR4 had a 1.78:1 or if that was exclusive to the XR6), and the XR6 has the small dia bullet 1.78:1 ratio case all the drag race/top end guys like to use.

I ran an '87 2.0 liter XR2 on my Viper and it was a great starter motor to learn to drive the boat at higher speeds. I can't say I spent much time wrenching on it other than the usual preventative maintenance (injection and module removal, fuel pump diaphragm, etc etc). I ran it pretty hard...spent most of its time @ 5-6K over the 2 yrs I had it.

My biggest question would be why did it overheat and how hot did it get?? Is it seized?? Do a compression and leakdown on it, go through the carbs, check the timing, check the stator and switch boxes, throw a new impeller and plugs in it and see if it runs. Did you have the heads off it?? If so, what did the cylinders look like?? Does it still have the injection on it?

[pcrussell50]

Use the search in upper right put in cherry red 2.0 look for TRex's info. He's the 2.0 guru
But BEWARE It may take ya a few days to larn ta reed hiz rittin dat he rote it in. LOL
Also his area is still not all better from the hard hit from the storm/water in La so he may not respond right away

when i searched, it only returned 4 threads started by a user name "trex", and three responses, with nothing about cherry red 2.0. is there anything more to help my search?
EDIT: just figgered out it's T-REX, and that usage gives returns some hits. i'll search his posts.
EDIT2: just went through all 10 pages of hits after searching for T-REX. none had titles like cherry red 2.0 :(

jeff thanks for all that info. it's HUGELY more about these motors than i knew going in.

(i started another thread about this, but it was apparently overheated idling in the driveway, because the PO's brother-in-law didn't think or know to put muffs on it.)

-peter

[Mini GT]

I might have a 2.0l XR2 150 on my rear.....runs hard and solid though.

[mr fun]

as i understand they had sleeves that were pretty beefy, and could withstand a pretty catastrophic failure with out harming the block. on the downside,,, they were very susiptable to salt, think cooling tubes, not to mention attacks on exterior bolts. on the up side, merc used the same block for it's formula motors (all the hardcore factoids will correct me here) which later became the sst120 series. on the downside, they all run bassakwards , so it gets expensive. :cheers: out

[pcrussell50]

sounds like maybe these XR2's are good, reliable fish/recreational motors? are they as reliable and easy to work on as v4 crossflows? (a tall order, i know ;) )

-peter

[Ira Tindale]

They are very reliable engines. They can take a pounding and keep turning. I love em.

[Da Bull]

The only thread by T-rex about a "cherry" motor is his Cherry 2.4 project and it can be found at By-U-Boyz.com and the auther says Raptor.

DB

[WATERWINGS]

I didn't read all the posts, but I have a 2.0 block and front 1/2 that I will probably never use, it has what looks to be almost brand new Wiescos.

If you want it, make an offer.

[T-REX]

Pre 91 2literz didn't actually have sleeves...the block wuz actually cast around tha castiron cyls, which made them tuffer than any other mota mercury ever built....U kin run a 2liter hot and even transfer aluminium off tha piston to tha cyl, and after remove'in tha aluminium, and a lil hone job, and it's good az new!!....The main problem with run'in tha mota(any mercury mota) hot, iz tha locator pin wanna turn loose after bein overheet'd.....JMO

[WATERWINGS]

Mike...is that 2 liter that I have worth building for a hot rod motor, or no ?

It an XR 2.0 150 I believe.....REAL thick cylinder walls and extra heavy....

[T-REX]

it's az good az any, and better than tha newer ones(az for thickness ov cyls...BUT, it takes a LOT ov machine?grinder work to make it run...and it will ONLY run a a very light bote!!

[mr fun]

do you use stock rods and pistons? aftermarket? what kind of r's? my dads ole 2 banger I got to 7 grand, no grindin, just bolt on stuff, stuck one at wot, told 93 octain was the culprit. 175-180 compression, it had the stock parts, told the pistons were good forged TRW originals w 3 rings, just wondering about the rods, I know the sst120's crank up more than 7, right? think fuel hurt me? shoulda been 100 octaine,,, would value your opnion oh great and powerful T :D:thumbsup:;)

[Da Bull]

I had my heads cut to make 180lbs on my 1980 175 2.0L and ran 100 octain aviation gas. 150lbs of compression is the cut off for pump gas. You can get away with more on a light boat but it`s not the norm. The good thing about av gas is that it is gov regulated to make sure it is 100. Can`t have airplanes falling out of the sky because of burned pistons. I never had a problem with av gas in any motor. It also has some lead in it.

DB

[T-REX]

7K iz not unsual for a STOCK ported 2liter ....But, it all depends on tha boat!!....I have run My F-1 2liter with 185#s ov comp with 93 octain fuel!!...I did it by accident at first, but leern'd what I could git away wit!!...Free wheel'in mota kan git away wit more comp and less octain than a loaded mota....I use tha small rods, big rods, and even tha top guided rods, and have had NO problems wit either!!...Have used stock ones, and lightened/balanced ones.....Pistons, tha early F-1 pissons wuz trw and Mahle, and I use them both...Theyz even anuther one , but I kan't remember tha name...I used Wiesco's in my Pro 120 mota, and wit tha rite break in, they work'd juss fine, and I never had a pin kum out ov one!!!....Altho, I never have seen a 2liter wit 3 rings...prolly kuz I ain't ole az U...lol

[Tom JM]

What's your idea of a "light boat" ... 600lb? - more/less?
Are the Cherry 2.4 piston mods recommended on the 2.0?
Ideal porting mods?
Which heads have highest stock compression?
Any other suggestions?
Ya, I might be interested in that XR

[mr fun]

from that lil green sprout T :D, I may be older than you but alot purdier:iagree:,,, since the world economy will be crashing in a year or so I may be selling a bunch of trick 2 liter stuff soon. I'll know on nov 7th, :cool:

[pcrussell50]

ok, next stupid question:

is the one i have really an XR2? when i do a serial number lookup, (s/n: 0A970455), i can only narrow it down to between '86 and '87.

BUT there are several different 150hp models within the serial number range of Axx to Bxxx, some are XR2's some are not. what's the difference between 150hp v6's that are XR2's and 150hp v6's that are not XR2's? and how do i tell which i have?

it says in various places on the cowling, (shoot me for saying black max) "black max", "150", and "oil injection"

-peter