S3 Cylinder Head Extreme Kit for RIEJU MR 250 & GasGas EC 250 Bikes (2018-2025) - (Red)
S3 Cylinder Head Extreme Kit in Red for Rieju MR 250 & GasGas EC 250. Smooth, progressive power for technical riding with improved traction and engine control.
| Brand: S3 |
| Color: Red |
| Head Kit Type: Extreme |
| Engine Displacement: 250 cc |
Internal Reference:
S3-XTR-1058-250-R
Product Information
The S3 Cylinder Head Extreme Kit is designed for riders tackling technical trails or extreme enduro terrain on their Rieju MR 250 or GasGas EC 250. By modifying compression, this kit delivers smooth, progressive power, giving riders improved engine control and better traction in tight, challenging sections.
Its engineering also reduces typical hot spots found on original cylinder heads, helping manage engine temperatures during prolonged technical riding. The Extreme Kit is ideal for riders who prioritize control and precision over raw torque, providing predictable throttle response in demanding conditions.
All components are designed for straightforward installation with OEM-level fit, ensuring consistent performance without compromising reliability.
Power Kit vs Extreme Kit
Feature | Power Kit | Extreme Kit |
|---|---|---|
| Compression | Modifies compression for one more usable gear, improving torque and mid-range power delivery | Modifies compression for smoother, progressive power, improving traction and control in technical sections |
| Heat Management | Reduces typical cylinder head hot spots | Reduces typical cylinder head hot spots |
| Riding Style | Aggressive enduro and fast trail sections | Extreme style riding, technical terrain, tight control |
| Throttle Response | Strong, predictable power delivery | Smooth, progressive power for better traction |
| Best For | Riders looking for more engine torque and an additional gear | Riders focusing on technical riding with precise engine control |
Both kits are engineered to maintain OEM-level fit and are easy to install on compatible bikes.
Tip: If you want strong torque and an extra gear for spirited enduro riding, go with the Power Kit. For technical trails and precise throttle control in extreme conditions, stick with the Extreme Kit.
Includes
- Cylinder head cover
- Cylinder head insert
- O-rings
Key Features & Benefits
- Progressive Power Delivery – Smooth, predictable engine response for better control.
- Improved Traction – Compression tuned for technical riding conditions.
- Heat Management – Reduces hot spots for safer operation during extreme use.
- Extreme Riding Ready – Optimized for technical terrain and precise throttle feel.
- Complete Kit – Includes all components needed for installation.
Fitment
GASGAS (2018–2020):
- EC 250
RIEJU (2021–Present):
- MR 250
Rider FAQ
Q: Will this kit work at low altitude?
A: Yes, but it is optimized for average altitude around 1000m to maintain compression balance.
Q: Does installation require engine modifications?
A: No major engine modifications are needed. The kit installs directly onto compatible cylinder heads.
Q: What comes in the kit?
A: Cylinder head cover, insert of your choice, and O-rings.
Q: Can this handle technical riding?
A: Yes. The kit is designed for smooth, controlled power and precise engine response under extreme trail conditions.
