how to tell a merc 2.0, 2.4, 2.5 apart visually ...

bsteckel

bsteckel

Junior Member
going to look at another motor on the way home today. how can i tell visually if it is a 2.0 or 2.5 motor?

is there anything i can look for so i am sure what motor it is?

thanks
 
yeah . . . I could write a book here. What years are you talking about? It should be pretty obvious.

Heads, carbs, intake, serial number, decals, block difference 2.0L vs. 2.5L (buldge . . . 92 and later).
Search screamandfly.com or get a factory manual. Can't the owner tell you what he's selling???
 
no .. all owner knows is that it is an 89 mariner 150 25"

it seems that most people out there do not know what they are selling. i am finding it very common. i have had people give me the wrong year ... some off by as much as 10 years .. maybe that was on purpose :bat:


the only number i can find on the motor is very hard to read .. i think it reads 06139606

these numbers were on a tag that is sort of worn off.
 
serial number is also on a freeze plug on the powerhead . . . also check the date on the starter (keep in mind some starters have been replaced). 92 (serial begins with "0D") was the first year of the 2.5L and 91 was the last of the 2.4L. 1988 and later 2.4L should have 1pc heads. Generally speaking the 150's were 2.0L except xr4, xr6, Mariner Magnum II/ III. 2pc top hat style heads (1983 - 1988) 135/150's will have a stamp 3 1/8 and 2.4L will have 3 3/8.

DSCN0892_Medium.jpg
 
92 and newer carbs will have a stamp on the side WMH carbs.

16's are 200hp carbs :)

wmh - 12 and 13 are 2.0L motors

wmh - 14, 15, 16's are 2.5L motors

DSCN0891_Medium.jpg



Old style wh- carbs . . . the stamp is on the top . . . 1990 and earlier.

wh-20 were the fastest . . . I have 2 sets off 2.4L v225's ;)
wh-22's are the second best 200hp carbs.

Diamond shaped heads are pre-83 motors . . . head bolts on the cylinder walls . . . no oil injection.
 
bsteckel said:
no .. all owner knows is that it is an 89 mariner 150 25"

it seems that most people out there do not know what they are selling. i am finding it very common. i have had people give me the wrong year ... some off by as much as 10 years ..
Click to expand...

That's right on par for the course . . . Welcome to my world. You'll learn to ask the right questions and save yourself the gas money and time.
 
ok .. here are some numbers ..

one the top freeze plug C139606

on the carburetor 1374-5427-0 or C then WH these numbers are on the top of the carbs
 
There are more numbers on the carbs . . . the carbs on C's are funny. The numbers aren't next to the "wh-". I'm almost 100% sure it's a 2.0L . . . I don't think merc made a 2.4L 150 in 89 except for the XR4 which I think was only 88. I don't have my book here, but I'd bet you it's a 2.0L. Did you buy it?
 
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i am waiting to make an offer until i know what it is for sure.. :head:

the other thing is i would like to check compression .. there are no wires with the motor ...


not sure where i can hook up the battery to spin it over .. as i have said before, this is my first boat project .. if it was a car, i would be ok.

i do not want to screw up anything trying to spin it over.

can you give me details on how to check compression? .. i have a gauge.

what else should i be looking for?

he told me that he just had to replacing something electrical on the motor .. his friend turned the battery switch to off on the boat when they were out .. when they ran the motor to get back home, something fried on the electrical side. not sure what it was, but he said he paid a lot of $$ to fix.
 
BS

IT"S ABOUT TIME!

bsteckel: For someone with lots of "car" experince I find it difficult to believe some mechanical knowledge isn't easily tranfer to an outboard? We are all working this hobby on a budget, but with outboard it has been my experince you get what you pay for. If you want to learn, buy a junker and dig in and go for it. There's nothing like hands on experince. At this point I'm not sure what anyone else could tell you - JUST DO IT and get it over with!

Kamikaze
 
thanks guys for the support. it seems on this board if you have not been lurking here for 20 years, then you are not worth of asking questions. i understand how many would think i have been dragging on about my outboard purchase, and you are right. i have had some issues where my motor budget got cut in half, so i am really trying to make sure i do not get burnt financially and get the best bang for my buck.

i searched this site for info on doing a compression test .. did not get much back. i know nothing about outboard electrical, charging, wiring, systems ... but i am sure if i do something wrong, it will cost money.

kamikaze .. not sure what your budget is and i really do not care. obviously you have not paid for something and gotten taken or you would not make such a stupid comment. sometimes you do not get what you pay for. maybe you can afford that, but i cannot. and sorry i do not have the years of boating experience you have. this is my fist project boat .. i can send you pics of the car i built in my garage and if you want to come see it, your are more than welcome. i just do not dive into things and get my hands dirty. that can become costly .. i try to arm myself with as much info as possible .. if this annoys you, sorry .. dont read my posts. i am sure some of the car stuff will transfer, but with all the wealth of info here, why would i not ask? not sure how a car motor would be real similar to a 2 stroke outboard, but if you say so .... also not sure how my car experience would tell me if the motor i was looking at was a 2.0, 2.4, 2.5 merc .. thought i would ask someone that works on these daily. i have done compression tests on cars, but the wiring was there and i turned the key to crank them .. this outboard is a little different. do not want to fry a relay, burn up the starter/wiring, etc.

BS has been a huge help with all of his posts, and so has FERM. A few others have also chimed in and i thank you for that ..

maybe i am too much a newbie for this site????

hope i did not overreact here .. i did have a stressful week at work.
 
Take care, your not the only one that has had their fill of stress this week. As far as the hot wiring the motor to spin it over for a compresion test, hook 12 V + to the starter selenoid( Folow the wire from the starter back), its a flat round selenoid, not like the ford type. Hook your battery up to the big pole that doesn't have the starter cable hooked to it, ground the negative cable to the starter bracket. Hook your remote starter to the terminal with the small yellow wire with a red stripe. That should power up the starter. The ignition will fire with out a key on switch( like a magneto), any time the flywheel is rotated, it will fire the coils, so be carefull, look for the black wire with the yellow stripe, ground that out and it will kill the ignition, or you can check the fire on each coil while you are testing the compresion by using a spark gap tester. Take a flash light( use a bore scope/light if you can find one), shine it in each cylinder with the plugs out, look at the edges of each piston for burn spots, look at the cylinder walls for scoring or signs of aluminum sticking to the walls. If you get real serious about it, show up with a set of head gaskets and a torque wrench, tell the seller you want to pull the heads, if you don't like what you see, put the heads back on with the new head gaskets and consider the head gaskets money well spent. If the seller isn't trying to hide anything, he shouldn't give you any crap about the head gaskest. But be prepared to pay his price if you don't find anything wrong, it goes both ways. These things are a bit different than auto engines, I got my start in the boat business working on I/Os and Inboards, after 22 years of working on boats, I'm still learning on outboards
 
spareparts ... thank you very much for that reply. im going to dig out my starter interrupt switch, comp tester, and a good battery with cables and give it a shot. i just did not want to power up the wrong place and smoke this guys electrical system. if it is mine and i break it, oh well .. but breaking someone else's stuff is not nice:bat:.

thanks again, i really appreciate it.

Brad
 
be careful with the battery cables, i use a set with ring terminals that I can bolt in place on the selenoids rather than using clamps, it keeps things from sparking. I shoud have replaied earlier to your question, I've been a bit stressed my self lately
 
no problem .. i appreciate the info .. i have some cable and will crimp some ends on to aviod sparking.. good idea.
 
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