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Online store run by Xpert Moto
Local pickup available for pre-orders only
On-site installation at our Lewisham workshop
Online store run by Xpert Moto
Local pickup available for pre-orders only
On-site installation at our Lewisham workshop
Online store run by Xpert Moto
Local pickup available for pre-orders only
On-site installation at our Lewisham workshop
Online store run by Xpert Moto
Local pickup available for pre-orders only
On-site installation at our Lewisham workshop
Call us at: 0433 880 748
Free shipping over $200 (excludes tyres and bulky items)
Need help? book@xpertmotogear.com.au
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- ➔ Cylinder Works (78 products)
The Cylinder Works complete cylinder kit is a ready-to-install top-end replacement for the Yamaha YZ250 two-stroke. Rather than sending a worn, scored or flaking cylinder away for re-plating and waiting on the turnaround, you fit a brand-new standard-bore cylinder that bolts straight on and looks near-identical to the original Yamaha item.
Everything needed for the rebuild comes in the one box, including a matched Vertex piston, cylinder head, top-end gaskets, wrist pin bearing and a power valve kit. The matched piston-to-bore pairing is what gives the kit its consistent ring seal, quieter running and longer service life.
It suits riders and workshops rebuilding a tired YZ250 top end, and anyone who wants a fresh, known-good cylinder rather than a reconditioned one. Please confirm the part suits your machine's model year before ordering.
- Complete bolt-on top-end kit for the Yamaha YZ250 two-stroke
- Brand-new cylinder — no re-plating or cylinder repair work required
- Standard bore, 66.400 mm cylinder diameter
- Matched Vertex piston supplied with the cylinder for consistent fit and ring seal
- Standard compression ratio, so no fuel or tuning changes are implied by the kit
- Cylinder styling and fitment closely mirror the OEM component
- Includes cylinder head, top-end gasket kit, wrist pin bearing and power valve kit
- Suits 250 cc two-stroke applications
- Cylinder
- Cylinder head
- Piston kit
- Top end gasket kit
- Wrist pin bearing
- Power valve kit
| Brand | Cylinder Works |
|---|---|
| Part Number | CW20009K02 |
| Barcode | 714205039993 |
| Type | Complete cylinder kit (top-end rebuild kit) |
| Cylinder Kit Type | Standard bore |
| Cylinder Diameter | 66.400 mm |
| Displacement | 250 cc |
| Engine Type | 2-stroke (2-cycle) |
| Compression Ratio | Standard |
| Piston | Matched Vertex piston |
| Fitment | Yamaha YZ250 |
| Includes | Cylinder, cylinder head, piston kit, top end gasket kit, wrist pin bearing, power valve kit |
- Confirm the kit matches your YZ250's model year and engine configuration before removing the old top end — power valve and cylinder designs changed across generations.
- Carry out the fit-up and all torque figures, tightening sequences and squish/clearance checks to the Yamaha service manual for your model; do not rely on generic values.
- Check piston ring end gap in the new bore before assembly, and confirm the wrist pin bearing and circlips are seated correctly with circlip openings positioned as the manual specifies.
- Use the supplied top-end gaskets and a fresh base gasket set-up as specified; avoid sealants on gasket faces unless the service manual calls for them.
- The cylinder bore is plated and ready to run — do not hone, deglaze, bead-blast or machine it, and never use abrasives or wire brushes inside the bore.
- Clean the new components with a lint-free cloth and clean solvent before assembly, then coat the bore, piston skirt and wrist pin bearing with two-stroke oil prior to first start.
- Run a proper break-in: several gentle heat cycles with varied light-to-moderate throttle, allowing the engine to cool between cycles, before any sustained hard riding.
- Use fresh fuel and a quality two-stroke oil at the premix ratio specified by Yamaha for your machine; lean or stale mixtures are the fastest way to damage a new piston and bore.
- Fit a clean, correctly oiled air filter and inspect the intake tract for leaks or dirt ingress — grit passing the filter will score the new bore.
- Keep the power valve components clean and free of carbon build-up, and inspect them at the service intervals in your manual along with the exhaust system.
- Inspect the piston, rings and bore at the top-end intervals given in the Yamaha service manual, and replace wear items rather than running them out.
- Store the kit in its packaging in a dry place until installation, and keep the bore lightly oiled if the engine will sit unused for an extended period.
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