HPSP RACING CYLINDER BLOCK COMPLETE KIT SET WITH PISTON Y125Z 57MM 59MM

HPSP Racing Cylinder Block Complete Kit is a big-bore cylinder block and piston set for the Yamaha Y125Z (125cc 2-stroke engine, stock bore 53.8mm), offered in 57mm and 59mm oversized bore options for performance builds.

• Complete cylinder block with matching piston kit
• Big-bore options: 57mm and 59mm (above the 53.8mm stock bore)
• Built for Y125Z engine performance rebuilds
• HPSP Racing genuine product

Brand

HPSP Racing

Product

Cylinder Block Complete Kit with Piston

Model/SKU

Yamaha Y125Z

Type

Cylinder block + piston kit

Main spec

57mm or 59mm bore (stock Y125Z bore is 53.8mm)

Compatibility

Yamaha Y125Z 2-stroke engine

Both 57mm and 59mm are big-bore upgrades over the stock 53.8mm bore, increasing displacement; 59mm gives a larger increase than 57mm. Bigger bore builds typically need matching porting, carburetor jetting and ignition timing adjustments to run correctly - this is not a stock-replacement part.

Installation requires a full top-end engine rebuild by an experienced 2-stroke mechanic, including gasket set, ring seating and re-jetting. Package includes cylinder block and piston kit as pictured; gaskets/other rebuild parts are not confirmed included.

HPSP Racing Cylinder Block Complete Kit with Piston, a 57mm/59mm big-bore upgrade for the Yamaha Y125Z.