VERTEX Replica Forged Piston for YAMAHA WRF 426, YZF 426 2000-2002

VERTEX offers this piston kit for YAMAHA WRF 426, YZF 426 2000-2002. The piston slides in the cylinder and takes the force of the air-fuel combustion, passing it to the connecting rod and crankshaft.

Why choose a forged piston?

Instead of simply being cast, a forged piston is hot-pressed under very high pressure and then machined: its metal is denser and free of air pockets.

• Stronger when hot: it copes better with high revs, overheating and detonation.
• Lighter for the same strength: less stress on the connecting rod and bearings.
• Good to know: depending on the alloy, it expands a little more and is fitted with more clearance; slight noise when cold is normal.
• Why does it cost more? Forging tools, full machining and surface treatments cost more than simple casting.

Why choose VERTEX?

Vertex has made its pistons in Italy since 1953 and has supplied KTM’s original pistons since 1996: molybdenum-disulphide coated skirt and Japanese rings. Its four-stroke pistons are forged from 2618 alloy.

When should you replace the piston on your YAMAHA YZF 426?

Harder starting, loss of power, blue smoke, oil consumption or a knock when cold: these are the signs of a tired top end.

No manufacturer hour figure for this model. Cross-Mania guideline: compression check every 30 h in hard use and every 60 h for leisure.

Specifications and fitting tips

• Material: Aluminium
• Piston compression: Standard
• Rings Quantity: Set
• Stroke: 4T

Available in several sizes: choose the one that matches your cylinder (stamped size or measured bore). Diameters: A = 94.93 mm, B = 94.94 mm, C = 94.95 mm.

Cross-Mania tip: Measure the cylinder bore before ordering: the piston must match your cylinder size. Follow the manufacturer's break-in procedure and replace the top-end gaskets at the same time.

Also needed with this part

• Top-end gasket kit : ITALKIT · ATHENA
• Spark plug : NGK · NGK CR8E
• 4-stroke engine oil : LIQUI MOLY 10W40 1 L · MOTUL 10W50
• Air filter : TECNIUM · TWIN AIR

Compatibility

Check the exact model and year of your bike in the list below before ordering.

Fits:
YAMAHA WRF 426 2002
YAMAHA WRF 426 2001
YAMAHA YZF 426 2002
YAMAHA YZF 426 2001
YAMAHA YZF 426 2000