Saving Old Seagulls

Hi,
Can anyone advise me please, having just bought a seagull I bought 5litres of EP 140 for the gear box, can I use this in a Mariner 2hp as well, I believe the correct oil should be 90 grade, will the thicker stuff make any difference >

can not see why not I do.

The insides of the Mariner gearbox are not made of the same corrosion resistant materials that a Seagull gears and bearings are made of.

Therefore use a recommended outboard engine gear oil which will contain emulsifiers and corrosion inhibitors to guard against the effects of water ingress.

I assume your Mariner gearbox has shaft oils seals?
The purpose of using the thickest oil available in an older Seagull is to permit a usable (thinner) emulsification when the water passes along the non sealed propeller shaft into the gearbox oil.
Which is why an annual oil change is recommended.
Very agricultural.
Use the oil recommended by Mariner to save the power lost pushing the gears around in thick Seagull treacle. You don't start with enough to waste. Marine gearboxes are supercooled rushing through the water - there is no heat to thin down the oil.

Thank you all for the advice. Having changed the oil and used it a couple of times I now have and oil water emulsion in the box, so I guess oil seals have gone.

You dont give any details of your Mariner.

You should be able to find an owners manual in the download center at http://www.brunswickmarineemea.com/;jse ... 6i5j4cl3g8
You will also find a year identifier there too although I find the one at http://www.storesonline.com/site/573683/page/599222 easier to use.

You will find exploded parts diagrams at http://www.crowleymarine.com/parts.cfm although possibly only for American made models

Thank you very much for that info, I had been searching for such links without success. Thanks.

Forgot to say it is a 2M 2hp which I now know is 1983/4

The Brunswick marine site is the only place I know of for Merc manuals.