The Yamaha YZ125 is a high-revving, precision-dependent 2-stroke engine where correct cylinder geometry and clearances are critical for performance and reliability.
This service is designed specifically for YZ125 cylinders that require a cast iron sleeve due to scoring, previous over-boring, or structural wear.
Our process restores proper bore geometry, sealing surface quality, and serviceability for future rebores.
Each cylinder is inspected, machined, sleeved, and finished using professional equipment to ensure consistent results and long-term durability.
YOUTUBE Video how we sleeve a Nikasil cylinder.https://www.youtube.com/watch?v=Ma68gdH2QQY&t=190s
Why Choose Us for Your YZ125 Cylinder Repair?
Extensive experience with Yamaha YZ125 2-stroke cylinders
Model-specific sleeve selection
Precision honing on a Sunnen honing machine for accurate clearances
Deck machining for optimal gasket sealing
Clear communication and approval before any additional work
Yamaha YZ125 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.