Athena S410485301003 Standard Bore Cylinder 54mm YZ125

The Athena S410485301003 is a standard bore replacement cylinder designed for 1997-2004 Yamaha YZ125 LC Factory models, featuring a 54.00mm bore diameter and 14.8:1 compression ratio. This cylinder is entirely engineered in Italy by Athena's R&D Department and coated with motor-nicksil, a nickel-silicon coating developed to obtain smoothness and optimal wear resistance.

Key Features:

• Standard bore size of 54mm for stock replacement applications
• Constructed from aluminum and lined with nickel-carbide coating for durable, reliable performance
• Can be installed without making any changes to the engine crankcase
• Developed to withstand the highest temperatures, pressures and stresses

Important Installation Notes:

• Must be used with Athena cylinder head S410485308001
• The cylinder head and base gaskets are specifically developed for Athena cylinders - do not use OE replacement gaskets
• Power valves must be purchased separately
• For 1997-1998 YZ125 LC models, you must replace the original exhaust muffler with 1999-2003 version, and for 1997-1999 models, 2 original Yamaha torsion springs (valve) year 2000-2003 are required

Athena's cylinder components are recognized worldwide for their performance, durability and reliability. This is a cylinder only - piston, gaskets, and other components sold separately.