The VIN is a unique 17-digit code that can be found on the frame of the motorcycle, usually near the steering head. The 10th digit of the VIN indicates the model year:
```
A - 2010
B - 2011
C - 2012
D - 2013
E - 2014
F - 2015
G - 2016
H - 2017
J - 2018
K - 2019
L - 2020
M - 2021
N - 2022
P - 2023
```
For example, the VIN "JYA2R09C6KA001234" would indicate a 2018 model.
2. Look for other clues.
In addition to the VIN, there are a few other ways to tell the model year of a Yamaha TTR 125 dirt bike:
- The color and graphics of the bike may have changed from year to year.
- The engine may have different specifications in different model years.
- The suspension and brakes may have been upgraded or changed in different model years.
If you are still not sure of the model year of a Yamaha TTR 125 dirt bike, you can contact a Yamaha dealer or the Yamaha customer service department for assistance.