Mariner four cylinder 50hp 2 stroke

Tremlett 15 said:
same engine as a Merc 500 50hp 4 cylinder, which is 45hp at the prop.

post the serial No. and we should be able to date it.
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+1
Underneath the Mariner decals it's the merc 4 cyl 50hp, originally from the 1960s. Nice strong indestructible engine. Zillions of them in service
 
Tremlett 15 said:
same engine as a Merc 500 50hp 4 cylinder, which is 45hp at the prop.
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Isn't it the one which was also labeled as "Super America"?
That's what I had on my very first boat, it survived my initial MoBo (and also waterski!) approaches, which tells a lot about its reliability... :)
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MapisM said:
Isn't it the one which was also labeled as "Super America"?
That's what I had on my very first boat, it survived my initial MoBo (and also waterski!) approaches, which tells a lot about its reliability... :)
1252314962.jpg
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That's an unusual animal MapisM. It was sold as the 40 generally, but detuned and badged "SuperAmerica" only for the IT market, presumably by the IT importer (who just stuck a decal on I think...). I have no idea but I guess the name "superamerica" has cachet in IT, seeing that Riva of course used it for their ultra-desireable big flybridge boats of same era (?)

Anyway I think the 40/25 was a much later design, with 4cyl power head made by one of the eastern JVs (Tohatsu or Yam). The engine Mavric has is the "classic" 4 cyl 50hp made and designed in Wisconsin (and later, made in Belgium). Different engine
 
Cheers lads will post serial number when its light only just finished work , so the general consensis is that ive paid a good price for a really good strong outboard ?

I also need an ignition key for it as the guy lost it where can i get one from ? or do i have to buy and fit a new barrel info on both would be gratfully recieved cheers steve.
 
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Had 50 merc brown band on my first mobo, great engine. Well done for steering towards a good unit in the end. Parts available for this unit and being a mariner brand it is a better buy for your purpose as the price of decent mercury units driven up by classic boat enthusiasts (some weird breed they are)

Btw, my guess at age - 1985
 
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jfm said:
That's an unusual animal MapisM. It was sold as the 40 generally, but detuned and badged "SuperAmerica" only for the IT market, presumably by the IT importer (who just stuck a decal on I think...)
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Aha, I see. Yep, I knew that this version was detuned for the IT market - in fact there's also a "25" label in the pic, because in those days the regulation allowed to helm boats up to 25hp with no license.
But it was also a 4 cyl, and after the removal of the obstruction in the intake manifold it also became a 50hp actually, not a 40. Well, that's what I was told, anyway.
Hence my thought that it could be the same beast. But coming to think of it, it was 700cc or so, IIRC. So, yep, different animal.

As an aside, I'm not sure why that name was so popular, to the point of being used by Riva, as you said.
Back in those days, if anything they were the IT boats to have a cachet in the US, rather than the other way round...
 
MapisM said:
Aha, I see. Yep, I knew that this version was detuned for the IT market - in fact there's also a "25" label in the pic, because in those days the regulation allowed to helm boats up to 25hp with no license.
But it was also a 4 cyl, and after the removal of the obstruction in the intake manifold it also became a 50hp actually, not a 40. Well, that's what I was told, anyway.
Hence my thought that it could be the same beast. But coming to think of it, it was 700cc or so, IIRC. So, yep, different animal.

As an aside, I'm not sure why that name was so popular, to the point of being used by Riva, as you said.
Back in those days, if anything they were the IT boats to have a cachet in the US, rather than the other way round...
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The Merc/Mariner 4 cylinder ( 500/50hp/45hp ) is 721cc, so may be the same unit ?

@ Mavric, the full throttle RPM range should be 5000 > 5500rpm, idle RPM in forward gear should be 600 > 700rpm, engine weight for el start model is 176lbs ( 80kg ), manual/pull start model 166lbs ( 76kg )
I have had my Merc 500 from new, since 1976 & is still going great, even on the original spark plugs !!!!!
At WOT fuel consumption is around 5gals per hour and at low speed ( canal/river use ) it would be about 2 gals per hour, ( WOT is the only way )......... oil/petrol mix is 50:1
I have the Merc/Mariner Service Manual for models 500/50hp/45hp from 1976 up, so if you need any info, I can scan a page & post it on here or PM/email it.
My Merc 500 ( 50hp at flywheel ) on our Tremlett 15 pushes a 17" alum 3 blade prop at 5425rpm giving a top speed one up @ 42.1mph
( measured at a classic speedboat event at Windermere )....... we have recently move house & I think the book with prop sizes/boat weights may have been put into storage...!!!!!

@ Firefly625...... " weird breeds "........who, us or the engines ?
and I too was thinking around 1985.....again my Mariner brochure from around that time is also in storage....
.
 
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Tremlett 15 said:
The Merc/Mariner 4 cylinder ( 500/50hp/45hp ) is 721cc, so may be the same unit ?
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Doh! You called the one bought by Mavric "Merc 500 50hp" in your previous post, so I assumed it was 500cc...
That's why I ruled out the similarity, in my previous post.
Now, I'm pretty sure mine was 4 cil and 7 hundreds something, but can't remember if it was exactly 721.
Oh well, no big deal anyway, that's not going to make any difference for the OP!
 
Tremlett 15 said:
The Merc/Mariner 4 cylinder ( 500/50hp/45hp ) is 721cc, so may be the same unit ?

@ Mavric, the full throttle RPM range should be 5000 > 5500rpm, idle RPM in forward gear should be 600 > 700rpm, engine weight for el start model is 176lbs ( 80kg ), manual/pull start model 166lbs ( 76kg )
I have had my Merc 500 from new, since 1976 & is still going great, even on the original spark plugs !!!!!
At WOT fuel consumption is around 5gals per hour and at low speed ( canal/river use ) it would be about 2 gals per hour, ( WOT is the only way )......... oil/petrol mix is 50:1
I have the Merc/Mariner Service Manual for models 500/50hp/45hp from 1976 up, so if you need any info, I can scan a page & post it on here or PM/email it.
My Merc 500 ( 50hp at flywheel ) on our Tremlett 15 pushes a 17" alum 3 blade prop at 5425rpm giving a top speed one up @ 42.1mph
( measured at a classic speedboat event at Windermere )....... we have recently move house & I think the book with prop sizes/boat weights may have been put into storage...!!!!!

@ Firefly625...... " weird breeds "........who, us or the engines ?
and I too was thinking around 1985.....again my Mariner brochure from around that time is also in storage....
.
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Thanks Tremlett will keep in touch incase i need info :cool:
 
Firefly625 said:
Had 50 merc brown band on my first mobo, great engine. Well done for steering towards a good unit in the end. Parts available for this unit and being a mariner brand it is a better buy for your purpose as the price of decent mercury units driven up by classic boat enthusiasts (some weird breed they are)

Btw, my guess at age - 1985
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Thanks firefly at last ive bought something right , cant find and many vids with this engine on the water apart from some guy in a red boat oh well will post my own when its out :rolleyes: but no one has told me about my ignition key problem as the guy lost it :(
 
Mavric said:
Thanks firefly at last ive bought something right , cant find and many vids with this engine on the water apart from some guy in a red boat oh well will post my own when its out :rolleyes: but no one has told me about my ignition key problem as the guy lost it :(
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sorry re the key......forgot about it...but my engine is a pull start so cant really help on that front.

you could give these guys a call to see what they say ( never used any of them but been told good for old parts etc )

Duncan Walker Outboards tel 0118 9478641

Bill Highan Marine 0161 7907678

Outboards Parts ( Kent ) 0162 2829390

American Marine ( ask for Hank ) 01789 461673


.
 
Mavric said:
Thanks firefly at last ive bought something right , cant find and many vids with this engine on the water apart from some guy in a red boat oh well will post my own when its out :rolleyes: but no one has told me about my ignition key problem as the guy lost it :(
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The same ignition key was used for years afterwards by Merc so is likely still available at Merc dealers. It is a low security, small key. Do you have the number off the barrel? IIRC my last key code was just "2F" - that tels you how simple a lock it was :) If you can get the code, a delaer can supply. If not, you need to buy a barrel complete with new keys. Alas you cannot buy a generic key/barrel becuase it has a push-to-choke function that switches a solenoid the closes the choke.

Well you could fit a generic key/barrel, and a separate switch for the choke I suppose. But the push-to-choke key was a nice feature and it would be a shame not to preserve it

BTW, on cold start you need to release (=open) the choke very soon after it fires, like 3-5 seconds or so. It wont want the choke is closed for say a minute, as you'd do on an old car.
 
jfm said:
The same ignition key was used for years afterwards by Merc so is likely still available at Merc dealers. It is a low security, small key. Do you have the number off the barrel? IIRC my last key code was just "2F" - that tels you how simple a lock it was :) If you can get the code, a delaer can supply. If not, you need to buy a barrel complete with new keys. Alas you cannot buy a generic key/barrel becuase it has a push-to-choke function that switches a solenoid the closes the choke.

Well you could fit a generic key/barrel, and a separate switch for the choke I suppose. But the push-to-choke key was a nice feature and it would be a shame not to preserve it

BTW, on cold start you need to release (=open) the choke very soon after it fires, like 3-5 seconds or so. It wont want the choke is closed for say a minute, as you'd do on an old car.
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Thanks lads lots of old sea dogs with plenty of knowledge on here :cool:
 
colhel said:
An excuse to post a wake shot!. My first boat about 25 years ago :D.... A well abused 4 pot Mercury
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Very nice Colin. The engine (on the right) not the photo :). That's a 1981 80hp, which is the 4 cyl 66cu in version of the 6cyl 99 cu in "tower of power"
 
MapisM said:
As an aside, I'm not sure why that name was so popular, to the point of being used by Riva, as you said.
Back in those days, if anything they were the IT boats to have a cachet in the US, rather than the other way round...
Click to expand...

Didn't Ferrari use the superamerica name on a couple of cars in the late fifties/early sixties?
 
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