| Component | Specification |
|---|---|
| Model Range | 2017 – 2020 (SEC3) |
| Engine Oil | SAE 10W-40 (API SG+, JASO MA/MB) | 0.9L (1.0L with filter) |
| Tires (F/R) | 120/70-15 M/C 56P / 140/70-14 M/C 62P |
| Tire Pressure | F: 2.0 bar | R: 2.25 – 2.5 bar |
| Spark Plug | NGK CPR9EA-9 (Gap: 0.8–0.9 mm) |
| Battery | YTZ7V |
The SEC3 generation of the Yamaha YP 125 R X-MAX represents a significant engineering milestone: it was the first 125cc scooter in Yamaha’s lineup to fully adopt the ‘TMAX DNA’ by utilizing motorcycle-type telescopic front forks. This design choice radically improved front-end stability and feedback, distinguishing it from the traditional ‘unit-swing’ suspension systems common in the urban mobility segment.
Engineering Analysis: The SEC3 Framework
Between 2017 and 2020, Yamaha refined the X-MAX 125 to meet Euro 4 emissions standards while enhancing its sport-touring capabilities. The SEC3 model features a liquid-cooled, 4-stroke, SOHC, 4-valve engine designed for efficiency. The integration of Traction Control Systems (TCS) as standard equipment during this era marked a shift toward high-tier safety features in the learner-legal category.
Maintenance Essentials
Lubrication System
For optimal thermal management and protection of the SOHC valvetrain, MotoSpecsLab recommends SAE 10W-40 engine oil meeting API SG or higher standards. The dry fill capacity is approximately 0.90 liters, but a full 1.00 liter is required when performing a standard filter replacement. Regular oil changes are critical for maintaining the longevity of the centrifugal clutch and V-belt transmission components.
Ignition & Electrical
The SEC3 utilizes an NGK CPR9EA-9 spark plug. Precise gapping between 0.8–0.9 mm is essential for consistent combustion and cold-start reliability. The electrical system is supported by a high-performance YTZ7V battery; given the Smart Key system’s constant parasitic draw, maintaining battery health with a smart charger during storage is highly recommended.
Chassis & Contact Patch
The X-MAX 125 SEC3 rides on a 15-inch front and 14-inch rear wheel configuration. Correct tire pressure is vital for the scooter’s signature agility:
- Front: 2.0 bar (29 psi)
- Rear (Solo): 2.25 bar (33 psi)
- Rear (Two-up): 2.5 bar (36 psi)
MotoSpecsLab Verdict
The Yamaha YP 125 R X-MAX (SEC3) remains a benchmark for build quality in the 125cc class. Its combination of a rigid chassis and sophisticated electronics requires disciplined maintenance but rewards the rider with class-leading dynamics. Owners should prioritize high-quality JASO-rated oils to ensure the longevity of the engine’s internal friction surfaces.