ATHENA piston kit for YAMAHA YZ 85 LW, YZ 85 SW from 2002 to 2021

ATHENA offers this piston kit for YAMAHA YZ 85 LW, YZ 85 SW from 2002 to 2021. 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 ATHENA?

Athena, the Italian manufacturer founded in 1973, is an original-equipment supplier to manufacturers such as KTM and Ducati: the same standards for your replacement parts.

When should you replace the piston on your YAMAHA YZ 85 LW?

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 15 h in hard use and every 30 h for leisure.

Specifications and fitting tips

• Bore: 52.95 mm
• Displacement: 85 cm³
• Piston material: 4032 aluminium alloy
• Style: Forged Big Bore
• Piston size: Standard size A
• 2-stroke pistons in 4032 silicon alloy

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 : ATHENA · CENTAURO
• Spark plug : NGK
• 2-stroke oil : LIQUI MOLY 1 L 3065 · LIQUI MOLY 1 L 3063
• Air filter : TWIN AIR · TECNIUM

Compatibility

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

Fits:
YAMAHA YZ 85 LW 2021
YAMAHA YZ 85 LW 2018
YAMAHA YZ 85 LW 2017
YAMAHA YZ 85 LW 2016
YAMAHA YZ 85 LW 2015
YAMAHA YZ 85 LW 2014
YAMAHA YZ 85 LW 2013
YAMAHA YZ 85 LW 2012
YAMAHA YZ 85 LW 2011
YAMAHA YZ 85 LW 2010
YAMAHA YZ 85 LW 2009
YAMAHA YZ 85 LW 2008
YAMAHA YZ 85 LW 2007
YAMAHA YZ 85 LW 2006
YAMAHA YZ 85 LW 2005
YAMAHA YZ 85 LW 2004
YAMAHA YZ 85 LW 2003
YAMAHA YZ 85 LW 2002
YAMAHA YZ 85 SW 2021
YAMAHA YZ 85 SW 2018
YAMAHA YZ 85 SW 2017
YAMAHA YZ 85 SW 2016
YAMAHA YZ 85 SW 2015
YAMAHA YZ 85 SW 2014
YAMAHA YZ 85 SW 2013
YAMAHA YZ 85 SW 2012
YAMAHA YZ 85 SW 2011
YAMAHA YZ 85 SW 2010
YAMAHA YZ 85 SW 2009
YAMAHA YZ 85 SW 2008
YAMAHA YZ 85 SW 2007
YAMAHA YZ 85 SW 2006
YAMAHA YZ 85 SW 2005
YAMAHA YZ 85 SW 2004
YAMAHA YZ 85 SW 2003
YAMAHA YZ 85 SW 2002