- Ideal engine part to complete Koso's big bore kit
- Unique four-valve design increases air flow and performance
- Provides more power and torque
- Features a forged piston, stainless steel 24 mm intake valves and 20 mm exhaust valves
- Proper exhaust system must be used to prevent re-flow pressure and heat.
NOTE: Only fits Koso 170 cc big bore kit.
| Compatible Vehicles | |||
| Years | Make | Make | Notes |
| 2014-2015 | Honda | Grom 125 | |
| 2017-2020 | Honda | Grom 125 | |
| 2018-2020 | Honda | Grom 125 ABS | |
| 2019-2021 | Honda | Monkey Z125M | |
| 2019-2021 | Honda | Monkey Z125MA ABS | |