Old Mariner 5Hp questions

[M1Tommy]

I have an old Mariner outboard. It runs OK.... 'won't expect anything incredible from a 5Hp.

OK, what gas/oil ratio do y'all think this critter should be running? I've been mixing 32:1, just on my own notions, but have never found anything more certain. If I'm running too rich, I figure I'm losing power and fouling my plug (it runs pretty sooty)... but I don't want to run w/out enough oil. I've no paperwork on the motor and can't find out anything about it on the 'net.

Now, here's a doozey.... is this critter water or air cooled? OK, after y'all get back in your chairs..... I see nothing comeing out of the motor when it's operating, like water leaving it as I've always seen from outboards that I know are water-cooled. There is what appears to me to be a water inlet tube or ... what???... just behind the prop... facing forwards... sort of bell/funnel shaped. It leads to a small tube that goes up into the lower unit's teeny shroud, then to parts unknown. All that said, while the cylinder has a shroud, it has a lot of what sure look to me to be cooling fins under it and around it... even the shrouded part. I've run the motor for 15-20 min. at a stretch in the lake. It's a pretty noisy motor, typ. to other air-cooled ones I've been around. But before I take off for a day...way down a creek or across a lake, I want to solve this mystery to my satisfaction.

I know, I could start tearing it.. I mean disassembling it, but would rather not unless need be, as in replacing a water pump-impeller.

How think y'all?

Advice/opinions are appreciated.

Tommy

P.S. Below is a link to a photo of the motor. It's a large photo, my apologies to the dial-up folks! The "intake" or whatever it is doesn't show up well. It's located just behind the tip of the uppermost prop blade. Those openings covered by a little square grating is the motor exhaust, and are very useful for blowing water out of a barrel all over the garage, motorcycle, van and work bench.

http://img.photobucket.com/albums/v2...g?t=1183738422

[kayaker]

http://www.outboardrepairs.com/mariner/
Here's a good place to start - I'd be no help though.

[M1Tommy]

I'll dig around on that site.
Thanks!
Tommy

[Barnacle Bill]

Got a model/serial no?

[M1Tommy]

Got a model/serial no?

not handy, but will after lunch.....:rolleyes:

Thanks!
Tommy

edit... stuck inside... will be evening before I get a serial #.
T

[jigsbydirk]

If it is the 1950's-late 1960 then you are running about the right mix. The older engines took more oil, also running mid to high octane gas will help their performance. I have a 1956 Mercury Mark 30 that i run 20:1 oil mix and high octane fuel. You still have to change the plugs every year, but that isn't too bad. I also like NGK V-power plugs under $2 a piece and work great.

You should be able to take the lower unit off easily and inspect your impeller. Usually there are 2 nuts at the base of the motor shaft that you can remove and take out the entire lower drive and then remove a plate at the base of your drive shaft and your impeller will be inside of there.

[Barnacle Bill]

If it is the 1950's-late 1960 then you are running about the right mix. The older engines took more oil, also running mid to high octane gas will help their performance. I have a 1956 Mercury Mark 30 that i run 20:1 oil mix and high octane fuel. You still have to change the plugs every year, but that isn't too bad. I also like NGK V-power plugs under $2 a piece and work great.

You should be able to take the lower unit off easily and inspect your impeller. Usually there are 2 nuts at the base of the motor shaft that you can remove and take out the entire lower drive and then remove a plate at the base of your drive shaft and your impeller will be inside of there.

That was my first thought Dirk but after a little looking I found that Mariner didn't make a 5HP until 1974.

[M1Tommy]

Family permitting I'll look this evening.
Which set of bolts (most likely) drops the lower unit, A? B? C? other???



Tommy... Umm, y'all let me know whether or not I actually got a photo to post OK, too.... :rolleyes:

[eddiebhome]

It's been a while, believe this is right.

[M1Tommy]

That grate-covered place marked "water intake" sure sounds and seems like exhaust outlet. It blows gases (and water of running in a big bucket) ALL over the place. I could believe that "other" fitting, behind the prop, is a water intake.

That said, why all the cooling fins around the cylinder and head? I'll take a few photos later today.

Thanks for the reply.
Tommy