Mariner / Yamaha,..are they the same?

[frustratedboater]

I have around the 1986 year Mariner 15hp (684C S 838421) and I'm in need of a short shaft lower unit. It is frozen up and suspected had water sitting in it for quite some time. I didn't get the chance to tear into it, but the drive shaft and the prop shaft won't turn and feels solid, almost "welded" in a sense.. so I think my diagnosis is pretty accurate.
I am wondering what year outboards will cross-over (fit) this motor in hopes to get this back up and running. The whole top half is in great shape but lower no so good.. Yes, I can always sell the top end, but I want to see if I can get one first. Any suggestions on year's that will fit this?

 

[matt167]

Mariner is one of 2 brands.. Yamaha or Mercury and it varies on the model number

 

[b20]

Mariner was using Yamaha for engines up to 60HP, and Merc for 70 and higher. Until the mid 80s. Then Merc bought the brand and transitioned to all Mercs. The way you tell the difference is by the serial number. Yamaha based engines use Yamaha serial numbers, which is what you have. It's usually a 3 group number, the first group being the model, like 684C, then a single letter, in this case the shaft length, S, then the engine individual serial number. Merc serial numbers are just 7 digits (until about 1986), or a number, a letter, then 6 digits, all in a single group, no spaces. 0G123456.

 

[Faztbullet]

Your serial number makes it a Yammy....

 

[frustratedboater]

Mariner was using Yamaha for engines up to 60HP, and Merc for 70 and higher. Until the mid 80s. Then Merc bought the brand and transitioned to all Mercs. The way you tell the difference is by the serial number. Yamaha based engines use Yamaha serial numbers, which is what you have. It's usually a 3 group number, the first group being the model, like 684C, then a single letter, in this case the shaft length, S, then the engine individual serial number. Merc serial numbers are just 7 digits (until about 1986), or a number, a letter, then 6 digits, all in a single group, no spaces. 0G123456.

Great info to have. At least I have something to go on here..

 

[frustratedboater]

Your serial number makes it a Yammy....

Given that mine is Yamaha, I guess the next bit of info needed is what years will fit this application. Since I've only been searching the two popular market place sites, I haven't found any around these early years, but knowing that Yamaha, or even Mercury units could fit helps. What years' of merc or Yam fit outside of 86'

 

[QBhoy]

Hi. If it helps. The 9.9 is the same unit. Your year is right on the change over for the most part I’d think. But it’s a Yammy