Mercury 4.0 outboard engine

[Coda]

I have acquired a nearly new outboard engine (short shaft) which has "Mercury 4.0" on the cover. I have no manual and can't find anything on line. I am fairly sure (from the weight) that it's a four stroke. I have taken the lid off but I can't see any sign of a sump. Can anybody tell me what fuel to use? And if it is a four stroke and if I can find a sump, what oil should I use? Finally, if anybody can tell me where to find an operator's manual, that would solve all my problems.

 

[VicS]

A 4 hp mercury could be a 2 stroke or a 4 stroke. If relatively new more likely to be a 4stroke

Although a "sump" may not be obvious if iti s a 4 stroke an oil filler low down on the port side of the power head should be fairly obvious

You should be able to find an owners manual here:- Brunswick Marine in EMEA Download Center - Download Center

Any brand of FC-W certified 4 stroke outboard engine oil will be suitable for a 4 stroke,

Any TC-W3 certified 2 stroke outboard engine oil , mixed 50:1, if it is a 2 stroke.

What is the serial number?

You should fit a new water pump impeller in a "new to you" outboard before use and check, or change, the gear case oil

Sorry for taking so long to answer your question

 

[VicS]

This picture from the owners manual shows the oil filler on a 4 stroke

 

[Coda]

Thanks for that useful information. The serial number is: OPO8995 (not sure if they are letter O or zero)

 

[Coda]

This picture from the owners manual shows the oil filler on a 4 stroke

View attachment 89895

 

[Coda]

ps ... and on first reading I missed your joke - it was certainly instant gratification!

 

[Pasarell]

Sounds like the 4 stroke but there is a number missing from your serial no I think. My Mercury 4.0 is OP409194 so if they are sequentially numbered and you've missed the 4 after OP it is from about 2005.
Good little engines that run from both integral tank and external tank so they have a fuel pump between tank and carburettor. Ridiculously expensive if bought from an outboard shop as I found out last year.
VicS is right about changing impellor and gear oil if not done recently. Also check the anode is OK.
I've just serviced mine and all a simple job. If you can't get the handbook online send me a PM with your e-mail and I can scan mine

 

[VicS]

Thanks for that useful information. The serial number is: OPO8995 (not sure if they are letter O or zero)

Zeros,
As Pasarell says I think you are a digit missing, but if it begins 0P089*** it makes it a Belgium made year 2000 model but cannot tell for sure if it is a 2 stroke or a 4 stroke .

The model number lists are on the same site as the manuals http://download.brunswick-marine.com/filereader/file/pdf/17/enen/outboard/us-europe.pdf for US and European made engines but only from 1963 to 2005

 

[Coda]

Sounds like the 4 stroke but there is a number missing from your serial no I think. My Mercury 4.0 is OP409194 so if they are sequentially numbered and you've missed the 4 after OP it is from about 2005.
Good little engines that run from both integral tank and external tank so they have a fuel pump between tank and carburettor. Ridiculously expensive if bought from an outboard shop as I found out last year.
VicS is right about changing impellor and gear oil if not done recently. Also check the anode is OK.
I've just serviced mine and all a simple job. If you can't get the handbook online send me a PM with your e-mail and I can scan mine

Thanks for that. I've double checked the serial number (it's very faint) and there definitely isn't a number missing. But I think maybe what I thought was a 2 at the end is actually a 7 - so it's OPO89957. It's very generous of you to offer a scanned handbook. I'm on the track of one, but I will contact you again if that falls through.

 

[VicS]

Thanks for that. I've double checked the serial number (it's very faint) and there definitely isn't a number missing. But I think maybe what I thought was a 2 at the end is actually a 7 - so it's OPO89957. It's very generous of you to offer a scanned handbook. I'm on the track of one, but I will contact you again if that falls through.

I cannot see any serial number with the number of digits you quote. They all have one more. You may need the correct serial number to identify the year model if you have to order any parts

You can down load owners manuals from the link I I gave earlier in #2. ........... Haven't you done that yet ?

The diagram , taken from the manual for the 4 stroke models , which I posted in #3 will enable you to determine if it is a 4 stroke. If it is a 4 stroke then there will be an oil filler
( There will also be an oil draining screw, the location of which is also shown in the manual)

If there is definitely no oil filler then its a 2 stroke

 

[Coda]

I cannot see any serial number with the number of digits you quote. They all have one more. You may need the correct serial number to identify the year model if you have to order any parts

You can down load owners manuals from the link I I gave earlier in #2. ........... Haven't you done that yet ?

The diagram , taken from the manual for the 4 stroke models , which I posted in #3 will enable you to determine if it is a 4 stroke. If it is a 4 stroke then there will be an oil filler
( There will also be an oil draining screw, the location of which is also shown in the manual)

If there is definitely no oil filler then its a 2 stroke

I typed the wrong number at first, sorry about that. As far as I can make out now, it's OPO89957. From your link, I downloaded the key to find out the year of build, but I can't see anything that starts with OPO8
Your diagram will be useful when I have a better look, at the moment it's not very accessible. I think it must be a four stroke because it's very heavy. Thanks for your help.

 

[VicS]

I typed the wrong number at first, sorry about that. As far as I can make out now, it's OPO89957. From your link, I downloaded the key to find out the year of build, but I can't see anything that starts with OPO8
Your diagram will be useful when I have a better look, at the moment it's not very accessible. I think it must be a four stroke because it's very heavy. Thanks for your help.

Thats better

The numbers in the lists are the earliest numbers for each year

If it's a 2 stroke 0P089957 lies between 0P059704, which is the earliest number for 2000, and 0P107432, which is the earliest number for 2001. Threfore it would have been produced sometime during 2000

The earliest number listed for 4 strokes is 0P109540 for 2001 therefore if its a 4 stroke it would have been produced before 2001. Probably during 2000.
Unfortunatelt the model number lists are incomplete ( IIRC a lot of information was lost in a fire) and do not discriminate between 2 strokes and 4 strokes , or even between different HPs.

In fact the parts lists show that the serial numbers for 4 strokes began with 0P073456, I guess in 2000, making yours a fairly early one.

I, afraid we come back to looking at your engine to see if it has the features of a 4 stroke or not. The oil filler will be the most obvious, I am sure.

This is the latest model. I notice that it has "Four Stroke" on the cover.