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Athena P400485100042 Big Bore Cylinder Kit (300cc) - 5.6mm Oversize to 72mm - 16.0:1 Compression


Generally ships to addresses in the contiguous United States the same business day if ordered by 12:15PM Central Time!

Kits include aluminum cylinder with nickel-carbide coating designed with larger water jackets.
Includes Forged piston, rings, clips and pin.
Athena top-end gasket set includes required seals and hardware.
Easy-to-follow step-by-step installation instructions.
Most are bolt-on; no machining required except where noted.
Rear Wheel Power 45.3 HP / 7600 rpm
Yamaha YZ250 2003-2018

Please Note: