Yamaha TT-R125 / TTR125 57.4mm Big Bore Cylinder Piston Kit
Brand new aftermarket big-bore cylinder and piston kit for compatible Yamaha-derived 125cc four-stroke engines using the matching cylinder layout.
Key Specification
- Nominal bore: 57.4 mm
- Piston pin: 15 mm
- Cooling: Air-cooled
- Engine type: Single-cylinder, four-stroke
- Big-bore application: commonly marketed as a “150cc” conversion
- Calculated displacement on a 54.0 mm stroke: approximately 139.7cc
- Condition: Brand New aftermarket upgrade/rebuild part
- SKU: 00105-ENG
Fitment
- Yamaha TT-R125 — selected 2000–2004 applications
- Yamaha TT-R125E — selected 2003–2009 applications
- Yamaha TT-R125L — selected 2000–2008 applications
- Yamaha TT-R125LE — selected 2003–2023 applications
Reference Information
- Standard Yamaha cylinder family reference: 5VL-E1310-00
- Later/superseding standard cylinder reference: 5VL-E1310-10
These Yamaha references identify the standard cylinder family only; they are not the manufacturer part number of this aftermarket big-bore kit.
Important Fitment Notes
- 57.4 mm / 15 mm-pin aftermarket big-bore kits are directly catalogued for TTR125-family engines.
- TT-R specifications vary considerably by year and market; compare the original cylinder and piston before ordering.
What's Included
The original listing confirms a cylinder barrel/block and matching piston. Additional rings, piston pin, clips or gaskets should only be treated as included if they are supplied with the physical kit shown in the product photographs.
Before Ordering
- Confirm the original cylinder is from the matching 5VL-style family
- Confirm a 15 mm piston pin
- Compare cylinder height, lower spigot, head-stud spacing and cam-chain tunnel
- Compare the oil passages and base/head gasket profiles
- Check crankcase opening clearance for the larger cylinder liner/spigot
Fuelling & Installation
A big-bore conversion changes airflow, compression and fuelling requirements. Carburettor jetting or fuel-injection calibration may require adjustment. Correct piston-ring orientation, cam timing, valve clearances, gasket preparation and running-in procedure are essential. Professional installation is recommended.
Road-Use Note
Increasing engine capacity can affect registration, insurance, licence entitlement and emissions compliance. The owner is responsible for confirming the legal requirements applicable to the motorcycle or ATV.
Shipping Estimate
Shopify shipping estimate: approximately 2.2 kg packed, with estimated parcel dimensions of 22 x 20 x 15 cm. Replace these estimates with measured packed weight and dimensions when available.