Ok, So after some more searching I uncovered a swedish post that clears alot up on older Mariners. The translation is rough but here you go:
Identify the model year
General rules
As mentioned earlier, the Mariner was originally a collaboration between Yamaha and Mercury Marine. In principle, the engines until the early 80th century divided so that the power mode for 60 hp engines as manufactured in Japan and the models coincide in prinip with Yamaha. Effects> 60 hp contrast is plucked from Mercury Marine. Mariner and Mercury have been working with a true clear identification of the engines, visually and a "map" of how it has been like running if you click on the following link.
... But
In reality, there are no sharp boundaries. In addition, picked it is not always the same models from Yamaha, which was present from the Japanese manufacturer that year. Ex. manner, it survived the two-cylinder 55-horsepower engine from the Yamaha well into the 90s as a Mariner, while Yamaha was the only one who called. "Original-engine".
You are different engines for both the manufacturing country (see below). Or click on the resp. power range may be to see our model directory:
2-8 hp, 9.9-20 hp, 25-30 hp, 40-55 hp, 60-275 hp
Mariner 'Made in Japan "- Yamaha
Japan - Mariner (Yamaha) has the typical structure of the serial: MMM-S-XXXXXX where MMM is the model, eg, "663". A single character between the model and serial number are talking about rigging the length S-Short, L-Long. Tal Rien then finished with the serial number which can be 5-7 characters long. Like any other Yamaha models are there also a sign of identification plate indicating year of manufacture - the same as the Yamaha.
Manufacturing - Literally ... and so we start
1973 - Z 1994 - Z
1974 - Y 1995 - Y
1975 - X 1996 - X
1976 - 1997 W - W
1977 - V 1998 - V
1978 - 1999 U - U
1979 - T 2000 - T
1980 - S 2001 - S
1981 - R 2002 - R
1982 - Q 2003 - Q
1983 - P 2004 - P
1984 - N 2005 - N
1985 - K 2006 - K
1986 - J 2007 - J
1987 - H 2008 - H
1988 - G 2009 - G
1989 - F
1990 - D
1991 - C
1992 - B
1993 - A
You can also determine the age by looking at the picture below:
Click image to enlarge ...
Mariner 'Made in the USA (and others) "(Mercury)
Mercury Marine / Brunswick - Made in USA (Belgiem / Canada / Australia ...)
The US-built engines are Mercury Standard model / serial number management. This means:
There is "no" model (Model Series)
Model series varies from country to country, where the engine is composed.
The model designation gives no clue about other things than just "model". F40ELPT - 4-stroke, 40 hp, electric start, Long shaft, power trim / tilt ...
The serial number always consists of eight (8) characters. Initially, only numbers with an initial "0": a (zero). U.S. engines may be early second digit replaced by a letter. The letters follow the alphabet so that the "A" by "B" and so on. As Brunswick also have realized the limitations of the alphabet (it ends after the W / Z) has started on a couple of years ago with "1" as the first digit. for example, "1A090000".
To find an engine production year you have to rely on tables set up in connection with the production.
