Used mercruiser engine... can someone help me identify it? (and other questions)
 

Hello. I want to repower my boat, but the budget is... slim... sadly.

Anyway, I have looked at a used engine that I am not 100% sure of which exact model it is, and what equipment its got.

The serial number is a little difficult to read, but I think it looks like 0W323688... There is a sticker on the ECU that seems to suggest its a Mercruiser 6.2 mpi made for mating to Bravo outdrives, from the early 2000s most likely?. I have tried emailing Mercury directly as well as two different mercury dealers, but no replies back as of yet...

I tried looking at Mercury Online Parts Lookup, but when I entered the serial number, it only showed all the possible variants it could be, e.g., 350 Mag, 6.2 Horizon MX, etc. I would like to know more precisely. (as I understand it, these engines are available with different equipment regarding fuel systems/coolers, etc.)

-If anyone can identify it and give my any pointers to where I can find a data sheet data sheet with specifications on external dimensions, fuel consumption per hour at WOT and power on the propeller shaft, suitable dimensions for fuel and air supply hoses in the engine compartment, etc., etc. I would be _very_ grateful.


-As of this moment, the engine is mated to a Bravo drive. Is it possible to connect it to an Alpha Gen 1 drive (which is what I got currently) without modifications, and if not, what is needed to do so?

-Really any information about the engine in question would be good...

BUT: Now to the thing that worries me a little when I started the engine while looking at it: As I interpret the scale on the oil pressure gauge in the boat, it shows about 18 psi immediately upon start-up, then slowly (in 20 seconds) creeps up to 31-32 psi at 1000 rpm. The ambient temperature at start-up was only about 40-45 F. Shouldn't the pressure be higher, especially considering the relatively low ambient temperature, and shouldn't the pressure rise faster?


The oil pressure gauge in the boat where the engine was installed was probably original from 1988. Is it common that they gives the wrong values as they age or can I assume it reads correctly (and is that a concern, as per above)?

Thanks to everyone reading this, regardless if you know any answers or not. Please excuse me if I ask stupid questions, I am a relative beginner in all this.. Cheers mates.

I wouldn't worry too much about the oil pressure...if you have ~10 psi for every 1000 rpm you should be good. A quick search on the 'Net shows that engine is a bit prone to low oil pressure, real or bad sensor reading, sludge build up, and/or worn oil pump.

Here's a post from this forum from a while back about a similar issue perhaps:
Mercruiser 6.2L MPI low oil pressure - Offshoreonly.com

Sorry for how vague this will be but it’s been a while.

The earlier 6.2’s had the top piston ring too close to the top of the piston and it was a weak point. So unsure if it was that way in 05, or how many hours on the one you are looking at.

Alpha requires a shift interrupt. If they are the same as what you see on 5.0mpi’s there is a plug from the sensor on the shift bracket that goes into the harness and I assume to the computer. 99% sure it is the purple wire.

Which computer does it have? There were some weird in between years where they were mefi 3 or the Motorola 555’s.

Hi everyone, sorry for not being able to reply for a few days. I want to thank all that have given me info.

I got a bit of a "bonus" for everybody... Some exhaust inspection pictures I took with my endoscope. I dont think they look all that great but.. Comments?

Is it just cosmetic or cause for real concern?

The boat will only be in freshwater from now on, for as long as I own it.

https://cimg2.ibsrv.net/gimg/www.off...cd423062f6.jpg
Inside exhaust channel in elbow


https://cimg3.ibsrv.net/gimg/www.off...65e4fe41e6.jpg
Outside of elbow


https://cimg4.ibsrv.net/gimg/www.off...1874166ac1.jpg
Beyond elbow "lip"


https://cimg5.ibsrv.net/gimg/www.off...08a09e7b05.jpg
Another angle of elbow "lip"


https://cimg6.ibsrv.net/gimg/www.off...db7e1d05d3.jpg
Looking toward the elbow cooling water outlets.


https://cimg7.ibsrv.net/gimg/www.off...73ecec2ab3.jpg
Inside Cooling water passage in elbow.


https://cimg8.ibsrv.net/gimg/www.off...30b84f3f5e.jpg
From elbow, looking at downward at manifold joint.

Thanks. I have since found it was mounted in a Hydrolift since new, presumably factory mounted. Your date checks out. Thanks again!

This is very good info, thanks a lot for you posting this! Unfortunately I couldnt get readings from above 1000rpm, and what makes me a bit concerned as well is that according to the gauge it was totally unaffected between 600 to 1000 rpm. Not any difference at all. I would expect at least a small single psi difference... but again, how is the gauge and the sensor one have to ask.

On a used engine never believe what previous owner says about oil change. Run engine up to temp maybe add a can of sea foam drain oil and put in fresh oil/filter, maybe a little thicker oil to, also wouldn’t worry about the lack of oil pressure rise between 600 and 1000 maybe old gauge/sender old wires, as long as you get 10psi per 1000 rpm

-I see (regarding the piston ring). And that would affect the oil pressure? Sorry I dont know enough to understand why, I thought the top rings were mostly for compression... Or are you naming it as a more general failure point?

-Yes I have one in my current engine, which is an older 1991 5.0 LX. Though I am unsure if they can be adapted to this one. I have heard something with the connection to the outdrive/drive shaft/something like that is different as well between engines that used bravo and alpha drive?

- I am not sure which computer it has, I didnt see any clear stuff that would inform me.. but perhaps you can identify something from this image?
https://cimg0.ibsrv.net/gimg/www.off...b315103e03.jpg

Thanks again for the answer!

Fully agree, its prudent to always be sceptical. Unfortunately, testing it more thoroughly at higher revs wasnt possible at this time. Which was a pity, to say the least. Thanks for the clarification regarding the lack of oil pressure increase with revs.