Mercury 4hp 2-stroke

[betterdrownedthanduffers]

Hello,

First post here! We've just (January) bought a Manta 19 - on a trailer at the moment, yet to be launched - and I'd like to do some maintenance on the second hand 4hp 2-stroke outboard we got with her.

I'll be the first to admit I know nothing about engines but I'm keen to learn quickly. So is there a good book or youtube video I can use to learn how to take the relevant parts apart, clean it, oil it, put it back together again, without breaking it? Is there anywhere I can get the manual? I've got the serial number, it's 9511512.

My other question relates to a problem I've already identified. There is a rotating switch on the outside of the engine that operates the fuel tank valve. This switch is attached to a linkage that goes to the valve (see picture). This linkage seems to be about 3-4 mm too short, so pops off the valve when it is rotated. Seems odd. Any ideas?

 

[VicS]

9511512 will make it a 1988 Belgium made model but I am not ceratin that is the serial number. It should be on an ID plate together with the model designation and the model year as illustrated in the owners manual

If you do not have the owners Operation and Maintenance Manual you should be able to find it in the Brunswick Marine in EMEA download center

Brunswick Marine in EMEA Download Center - Download Center

maybe this one
http://download.brunswick-marine.com/filereader/file/pdf/4/enen/outboard/2005/2-stroke/10102050.pdf
or
http://download.brunswick-marine.co.../4/enen/outboard/2006/2-stroke/10102060_1.pdf

If not you will have to browse the list for the right one

You should find this service manual Boatinfo - 1965-1989 Mercury Service manual for 2-40 hp on the boatinfo website covers your engine.

As the new owner of an engine unknown to you you should change the gearbox oil and fit a new water pump impeller.
If the old oil is milky or anything other than "clear and bright" it indicates water intrusion and that the gearbox seals should be replaced

Cannot help with the fuel tap .. sorry

 

[VicS]

With luck this is the right parts list

Mercury 4 to 5HP Parts for Serial Range 9477830 - 9589153 | Boats.net

 

[betterdrownedthanduffers]

Thanks for your help. The serial number is on a plate below the words "Serial number" and above the words "Made in Belgium" so that sounds plausible!

Thank you also for the manual links - I can't easily tell the difference between some of those manuals but they look like the right engine (I guess only tiny changes between models)

 

[betterdrownedthanduffers]

I think I need a fuel cock rod tube ...

 

[Refueler]

Apart from what VicS said - they are a good reliable engine and not really much needs to be done ...

I would recc'd a good flush in fresh water regularly to get rid of salt in the waterways ...

My next tip will have a few say no necessary - but I always do it and I have no trouble starting my engine next trip :

When finishing with engine and not going to use again that day ... turn OFF the fuel and let it run dry and stop ... Only use the stop button if you anticipate a short stop ... I have loads of engines and they all appreciate that method.

 

[anoccasionalyachtsman]

Have you checked that the tank is assembled correctly on its seats? (I'd expect to see rubber washers under those big washers, and it might explain how the rod shrank?).