Sinnis K157FMI 125 57mm Cylinder & Piston Kit – EGR Type
Brand-new unbranded standard-bore cylinder and piston kit for selected Sinnis 125 motorcycles using the K157FMI engine family.
Key Specifications
- Engine family: K157FMI / 157FMI GS-style
- Displacement: Standard 125cc application
- Standard bore: 57 mm
- Engine stroke reference: 48.8 mm
- Piston-pin reference: 14 mm
- Cooling: Air-cooled
- Engine type: Single-cylinder 4-stroke
- Cylinder style: EGR / secondary-air-system type
- Condition: Brand new
- Type: Unbranded aftermarket replacement
What's Included
- 1 x cylinder barrel
- 1 x piston
- 1 x piston ring set
- Head and base gaskets
Vehicle / Engine Compatibility
| Make | Model / Engine | Years / Scope | Notes |
|---|---|---|---|
| Sinnis | Apache 125 | 2008–2016 documented K157FMI | Verify exact emissions/cylinder version |
| Sinnis | Blade 125 | 2007–2016 documented K157FMI | Verify exact emissions/cylinder version |
| Sinnis | Cafe / Max 2 / Retrostar / Scrambler / Stealth / Trackstar / Vista 125 | documented K157FMI applications | Year ranges vary by model |
Important Fitment Information
Sinnis used K157FMI engines across several models and years. Confirm the exact cylinder casting, EGR/secondary-air fittings, piston profile and 57 mm bore before ordering.
Do not order by 125cc capacity alone. Before purchase, compare the original engine code, 57 mm bore, piston-pin diameter, piston crown/profile, cylinder height, stud spacing, gasket profile, oil passages and EGR/secondary-air ports with the existing engine.
The K157FMI family was used across carburetted and fuel-injected motorcycles, and production changes can affect top-end components. This kit should only be used where the original parts match the standard 57 mm K157FMI EGR-style configuration.
Installation
Correct piston-ring orientation, piston direction, valve timing, gasket installation and cylinder-head torque are essential. Professional installation is recommended where the correct engine-building procedure is not known.