Dating your yamaha guitar
Yamaha serial numbers are recycled every ten years, 29 formats are supported here based on research available on the yamaha website.There is some overlap between formats and in those cases multiple results will be generated. YMMI (Yamaha Music Manufacturing Indonesia), Made in Indonesia, 1990-1996: ########.
The remaining four digits denote the instrument’s sequential number of manufacture among all the instruments made during the month indicated.
The following two digits denote the month, and the remaining four digits denote the instrument’s sequential number of manufacture among all the instruments made during the month indicated.
For example, serial number 46090002 indicates a guitar built in 2008 (1962 plus 46 years), in September of that year (09), and that it was the second guitar made that month (0002).
The third letter is the month; June (see chart above.) The first and second numbers (following the 3 letters) are the day; 18th. Made in Japan, 1984-1986: Letter-letter-letter-letter-###.
The third and fourth numbers are the month; 02=February. The first two letters are the year; Q=0 and I=2, so 2002. (See chart at the top of the page.) The first letter is the year; 1985.