Outboard leaking gear oil.

[LONG_KEELER]

I did a gear oil change to this 2 stroke 4hp outboard round about this time last year. Didn't use it on the dinghy this season because of covid.
I noticed a pool of clean gear oil leaking on the floor of the shed. It's leaking from the bottom water intake slit as in the picture. I poked a wire into the gear box oil and there is a fair amount still in the outboard.

It's old, probably 1980's, and it's surprisingly powerful , so would like to carry on using it but fear that parts might be unavailable. Should I just leave it ?

Any ideas as to where the oil might be coming from ? and is it worth keeping. Pumps water fine and starts easily.






TIA

 

[CraigandHan]

A lot of this will depend on how you have had the outboard testing, I.e has it been tilted or just left straight down?
The only real way you are going to be able my o check is I’d suggest stripping the bottom unit taking the impeller out and shining a torch down,

failing that it’s the proper off and gear case out.. there are a number of seals but I can’t honestly remember the seals between the water intakes for me this is generally an enclosed unit but cannot think. Possibly a drive shaft seal, only way to be sure is to inspect.

 

[RichardS]

Possibly a drive shaft seal, only way to be sure is to inspect.

+1

A shaft seal sounds most likely. Actually changing the seal will probably be quite straightforward once you get the leg stripped down .... but that is likely to be the tricky bit.

Richard

 

[VicS]

I did a gear oil change to this 2 stroke 4hp outboard round about this time last year. Didn't use it on the dinghy this season because of covid.
I noticed a pool of clean gear oil leaking on the floor of the shed. It's leaking from the bottom water intake slit as in the picture. I poked a wire into the gear box oil and there is a fair amount still in the outboard.
It's old, probably 1980's, and it's surprisingly powerful , so would like to carry on using it but fear that parts might be unavailable. Should I just leave it ?
Any ideas as to where the oil might be coming from ? and is it worth keeping. Pumps water fine and starts easily.
TIA

IF it really is gear oil it can only leak via the prop shaft seals ( which it clearly isn't) the drive shaft seals below the water pump , the shift rod seal ( boot) or the gasket on the top of the gearcase (not sure about this last one though)
The drive shaft seals and the shift rod seal ( and the gasket) are all above the oil level so it wont leak from any of those unless its been laid down.

If you are sure its gear oil its gear case off ...drain and do a pressure test if possible otherwise inspect the shift rod boot change if necessary ( change it anyway) and also change the drive shaft seals ( note they are fitted back to back). Dont attempt to reuse the gasket

Exploded diagram and parts list here: Mercury Outboard Parts by Year (Mercury, Mariner, Mark, Force, Chrysler, Sears, SportJet) Mariner Outboard OEM Parts Diagram for Gearhousing Assembly | Boats.net although may not be exactly the right year model

Identify the year and/or quote serial number when ordering parts.
( For Mariner parts I'd go to Oakley marine in Brighton ( AKA Outboards-Direct) :: OutBoards-Direct ::

BTW , ITYWF that its a rebadged Yamaha. Worth keeping while it does not cost shed loads of cash and spares are available ...

 

[dgadee]

My mariner 3.3hp 2 stroke (looks new) has prop seal problems - twine appears to have been caught. Any suggestions for info on how to replace these?

 

[RichardS]

My mariner 3.3hp 2 stroke (looks new) has prop seal problems - twine appears to have been caught. Any suggestions for info on how to replace these?

That should not be too difficult if you can remove the prop and then unbolt the lower prop shaft casing and pull the shaft assembly out.

Richard

 

[VicS]

My mariner 3.3hp 2 stroke (looks new) has prop seal problems - twine appears to have been caught. Any suggestions for info on how to replace these?

I think simply prop off , bearing housing off, remove bearing and seal ( only a single seal by the look of things) fit new seal ( spring side facing inwards) replace bearing. Reassemble with new O ring
Unless it is an early one without F&N gears in which case prop off , water pump cover. impeller and housing come off.

 

[dgadee]

Thanks. Will order seals and give it a go. Haven't missed it at all this year - rowing is such pleasant exercise.

Was anchored yesterday beside a hardy Scot who swims to and from his boat. Maybe saving petrol costs.

 

[dgadee]

Ps anyone have a pdf of the workskop manual or parts breakdown? My one has the gear lever.

 

[VicS]

Ps anyone have a pdf of the workshop manual or parts breakdown? My one has the gear lever.

The link I have to a workshop manual is not working.

Exploded diagrams and parts list are available on several American parts suppliers websites.
I usually refer to Boats.net: Outboard Motors, OEM Marine Parts, Boats for Sale (Mariner are listed under Mercury by their American serial numbers)

 

[LONG_KEELER]

Thanks to all for the assistance.

Special thanks to VicS for finding the parts breakdown.

I've been able to identify the serial number of 6E0-023332 made in Japan. This may help getting parts. Who knows , there might still be some around.

I've decided to split the leg and investigate as suggested. Will be a nice lockdown project.

 

[VicS]

Thanks to all for the assistance.

Special thanks to VicS for finding the parts breakdown.

I've been able to identify the serial number of 6E0-023332 made in Japan. This may help getting parts. Who knows , there might still be some around.

I've decided to split the leg and investigate as suggested. Will be a nice lockdown project.

Thought it looked like a Yamaha

The serial number makes it a 1982 model

There aren't a lot of parts available but the boot, seals and gasket mentioned above are . The bearing housing O ring is not however. You might have to make one with O ring cord.