Questions about year/maintenance of 25hp Mariner

Hi,

New to the forum here. I've just aquired a 25hp Mariner. The model number on the plate is W25ML, serial number is 371904. From perusing this forum, I gather the motor is manufactured in Japan, and should be a 1989 model. Am I correct in my findings?

From initial testing (in a water drum), the motor starts, idles and revs.

I live in Uganda, where parts are next to impossible to source. I am traveling to the states in May, where I want to pick up some maintenance parts (card repair kit, fuel pump kit, thermostat, water pump impeller, plugs, wires, air filter). Any other suggestions? Any recommendations as to where to buy these on the web?

I cannot seem to find what type of fuel connector this engine uses. It appears to be Yamaha. Would that be correct?

I also wanted to get a maintenance manual. On West Marine site, I am looking at the Seloc Repair Manual - Mercury Outboards, 1965-1989, 1, 2cyl. models, 2-40HP, part number 1404. Would this be the correct one?

I intend to mount this motor as an emergency backup on my 30ft Alpa sailboat, as I am circumnavigating Lake Victoria. My max hull speed is 6 knots, but at present with my 12hp inboard diesel, she cruises quite happily at 5.4 knots. Any recommendations on prop pitch? At present, there is no prop on the engine.

TIA for any help
Pete

Yes, you appear to have a 1989 "Work" model Mariner.

I am not familiar with the differences between these and the regular line to be able to say whether or not the parts are the same or even if the Seloc's manual would be applicable completely.

There were three different versions of the 25 Mariner (built by Yamaha for Mercury).

There was the simply the 25 horse "C" model (in electric or rope start) that was widely marketed.

There was also the Work version and the Kerosene models that were primarily marketed in Asia or other areas where quality unleaded gasoline is more difficult to come by.

However, while Merc does have a different parts list for the Kerosene models (25K), there does not appear to be a separate listing for the Work models which "may" be included in their listing for the 25 "C" model Mariners (I just don't know).

I have never seen either a work or k model Mariner - my very limited experience with engines modified such as these is with OMC's "commercial" motors (normally produced in Hong Kong) which were built for similiar circumstances.

With those they used different sparkplugs and ignition components compared with the "retail" versions of the same motor which is why I can not say whether or not your model would use the stock parts for the normal C model.

The aftermarket places such as Sierra never produced alot of parts for the Yamaha/Mariners, it's kind of hit/miss. The operator of this site may be able to supply some of what you are after (but they only ship within North America).

I would suggest that you email the guys at www.mercruiserparts.com and tell them what you have and what you are after. They are a huge, on-line Mercury parts supplier (located in Florida) with some very knowledgable parts guys who can often advise what will "retrofit" if an original part has been discontinued.

All the Mariner models did use a Yamaha style (bayonette) fuel connector which was also used on most of the Mercury models (25 horse and under), however, you can use pretty much anything you like. I converted all my small Mercs over to OMC bayonette connectors because they are 1) cheaper in cost and 2) since I run both OMC and Merc motors, now all my fuel lines/portable tanks are interchangeable, so I never grab "the wrong one".

Since you plan to use this motor on a "displacement hull", the normal prop selection method doesn't apply. I would suspect that you should be looking for a low pitched prop, perhaps a 7 pitch, which may be the low end of what is available for that model (but I am no expert at prop selection for displacement or semi-displacement hulls and questions about them are almost non-existant in this particular forum - persons familiar with sailing craft can probably give you a better recommendation on that one).

Thanks for this. It should get me a bit further. Makes sense this model is a bit difference. We don't often get unleaded here, and our petrol is usually 'stretched' with kerosene. I've had to convert my two carburated cars to fuel injection because the float keep getting eaten.

Pete