KTM 125 SX Cylinder Repair – Precision Small-Bore 2-Stroke Resleeving
The KTM 125 SX is a high-revving, small-bore two-stroke that depends heavily on precise cylinder geometry, sharp port timing, and stable piston clearance. Even minor cylinder damage or worn plating can significantly affect power delivery and reliability.
MotoMonk offers a dedicated KTM 125 SX cylinder repair and resleeve service using a model-specific cast iron sleeve. This approach ensures durable port edges, consistent bore geometry, and long-term serviceability—critical for engines that operate at sustained high RPM.
YOUTUBE Video how we sleeve a Nikasil cylinder.
https://www.youtube.com/watch?v=Ma68gdH2QQY&t=190s
Why Choose MotoMonk for Your KTM 125SX Cylinder Repair?
Extensive experience with KTM 125 SX and other small-bore race engines
Resleeving optimized for high-RPM reliability and ring life
Stable bore geometry for crisp throttle response and clean jetting
Future serviceability through oversize piston options
KTM 125SX Cylinder Repair / Resleeve
✅ Cylinder sleeved with a model-specific cast iron sleeve
✅ Precision machining for sleeve installation
✅ Port chamfering after sleeving
✅ Final bore & professional honing on our Sunnen honing machine
✅ Cylinder deck machined for optimal gasket surface👉 Optional: Porting services are available upon request. Please contact us before work begins if porting is desired.
What’s Not Included
All parts (including the sleeve)
Piston, rings, bearings, studs, gaskets, seals
Power valve service, cleaning, or repair
Shipping & handlingCylinders must arrive fully stripped. Studs, gaskets, power valve components, and all attachments must be removed. Cylinders received assembled will incur additional labor charges.