Yamaha YB125 / YB125ZR Inlet & Exhaust Valve Pair – 1JP
Brand-new unbranded replacement inlet and exhaust engine-valve pair for compatible Yamaha models using the 1JP / 5VL valve-reference family.
Valve Specifications
| Valve | Head Diameter | Stem Diameter | Overall Length | Yamaha Reference |
|---|---|---|---|---|
| Inlet / intake | 25.90–26.10 mm service specification | 4.975–4.990 mm | Approx. 64.2 mm | 1JP-E2111-00 / 5VL-E2111-00 |
| Exhaust | 21.90–22.10 mm service specification | 4.960–4.975 mm | Approx. 63.3 mm | 1JP-E2121-00 / 5VL-E2121-00 |
Yamaha's YBR125 service data specifies nominal 26 mm inlet and 22 mm exhaust heads with approximately 5 mm stems. Independent replacement-valve catalogues give approximately 64.2 mm inlet and 63.3 mm exhaust overall lengths.
Vehicle Compatibility
| Model | Verified Scope | Fitment Basis |
|---|---|---|
| YB125 | 2013, 2014, 2018, 2019, 2022 and 2026 catalogue applications documented | Exact 1JP/5VL valve family |
| YB125ZR | 2018 BH73 catalogue application documented | Exact 1JP exhaust application; part-family catalogue assignment |
Important Fitment Information
Yamaha YB125 model codes vary significantly by market. Use the 1JP/5VL valve references as the primary compatibility check.
Yamaha reference numbers are supplied for fitment identification only. This is an unbranded aftermarket valve pair and is not represented as Genuine Yamaha.
Before installation, compare the original valve head diameter, stem diameter, overall length, keeper/collet groove and seating face. Cylinder-head condition, valve-guide clearance and valve-seat condition must also be checked.
What's Included
- 1 x inlet / intake valve
- 1 x exhaust valve
Installation
Correct valve seating, guide clearance, spring assembly, valve-clearance adjustment and cam timing are essential. Professional cylinder-head inspection and installation are recommended.