Mariner 2hp overheating issue

[slawosz]

Hi,
today my dinghy Mariner 2hp after 2-3 minutes of running started to get lower revs slower and slower (for like 1 minute), and then died. After 5 or 10 minutes I was able to start it again. Metal handle on the back was very hot, so I suppose it has issue with overheating, additionaly, telltale is not pumping any water. Also it has some strange smell, but hard to say exactly what it could be.
I found 2 guides how to disassamble the engine:
http://inadee.co.uk/marineroutboard.htm
https://www.troppo.co.uk/odds/Mariner 2M Impeller replacement.pdf

Engine looks quite easy to service alone, should I get this replacement kit?
https://www.ebay.co.uk/itm/Water-pu...528151?hash=item340d8b3c57:g:MFcAAOSweUNbHtY0

Or impeller only would be enough?

Also, there are 3 small holes, above propeller, on the leg, those were bit blocked, but not sure if it is water intake. I might hit bottom (mud and gravel) with engine, maybe its just blocked?

 

[VicS]

Hi,
today my dinghy Mariner 2hp after 2-3 minutes of running started to get lower revs slower and slower (for like 1 minute), and then died. After 5 or 10 minutes I was able to start it again. Metal handle on the back was very hot, so I suppose it has issue with overheating, additionaly, telltale is not pumping any water. Also it has some strange smell, but hard to say exactly what it could be.
I found 2 guides how to disassamble the engine:
http://inadee.co.uk/marineroutboard.htm
https://www.troppo.co.uk/odds/Mariner 2M Impeller replacement.pdf

Engine looks quite easy to service alone, should I get this replacement kit?
https://www.ebay.co.uk/itm/Water-pu...528151?hash=item340d8b3c57:g:MFcAAOSweUNbHtY0

Or impeller only would be enough?

Also, there are 3 small holes, above propeller, on the leg, those were bit blocked, but not sure if it is water intake. I might hit bottom (mud and gravel) with engine, maybe its just blocked?

Unless it has been run dry a replacement impeller will probably be all that the water pump requires but impossible to know for sure until the pump is opened up..

It sounds as though the cooling system may be bunged up with mud etc. You may be able to flush it lelar with a hose attached ot the water tube once you have removed the gearcase unit. Otherwise you may have to separate the power head from the leg and remove the cylinder head to get it properly clear.

The 3 holes shown in your second link are the water intake

Take great care when unbolting any of this engine or you will break the bolts . Many outboard mechanics will not touch such old engines for this reason.

You will find a workshop manual on the boatinfo website http://www.boatinfo.no/lib/library.html#

 

[slawosz]

Thanks!
Can I remove gear unit only by unscrewing 2 bolts which are holding lower leg, or I need to unlock shaft from gearbox as in one of above links?

 

[VicS]

Thanks!
Can I remove gear unit only by unscrewing 2 bolts which are holding lower leg, or I need to unlock shaft from gearbox as in one of above links?

I think you will have to release the drive shaft from the gearcase but it may depend on age /serial number which you do not quote. You may be able to remove the gearcase c/w shaft but have to then release it in order to do the water pump impeller.

There are genuine Mercury-Mariner manuals on the boatinfo site. You should find all you need to know there

 

[slawosz]

Thanks. I might actually be stupid enough to let it dry run for 30 seconds or so. I had to do like 15 pulls in order to start it before.

 

[slawosz]

There are genuine Mercury-Mariner manuals on the boatinfo site. You should find all you need to know there

I am afraid one for Mariner/Yamaha 2 hp is unfortunately missing.

 

[gordmac]

You might have overheated it, make sure it isn't siezed and still has compression before doing anything else.

 

[VicS]

I am afraid one for Mariner/Yamaha 2 hp is unfortunately missing.

Oh . Rats. Sorry.

I thought this one would cover it ( but I now realise its a Selc manual not the OEM one ). What year is your engine ? You did not say.

http://www.boatinfo.no/lib/mercury/manuals/mercury_1965-1989_2-40.html#/0.

Is there anything in the Yamaha section on the same site that would be relevant? No I suppose if it is older than 1984.

 

[slawosz]

You might have overheated it, make sure it isn't siezed and still has compression before doing anything else.

I hope its not. I manage to run it after 5-10 minutes.

Oh . Rats. Sorry.

I thought this one would cover it ( but I now realise its a Selc manual not the OEM one ). What year is your engine ? You did not say.

http://www.boatinfo.no/lib/mercury/manuals/mercury_1965-1989_2-40.html#/0.

Is there anything in the Yamaha section on the same site that would be relevant? No I suppose if it is older than 1984.

Will check later. I will try to disconnect leg in the evening. Will let know how it went in another thread, I posted there already.