Wössner Pro Series Forged Piston for GAS GAS ECF 350, MCF 350, KTM EXC-F 350 WESS, EXCF 350 and HUSQVARNA FE 350 2020-2023

WOSSNER offers this piston kit for GAS GAS ECF 350, MCF 350, KTM EXC-F 350 WESS, EXCF 350 and HUSQVARNA FE 350 2020-2023. 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 WOSSNER?

Wössner has forged its own pistons since 1994: Molykote-coated skirt to reduce friction and ease running-in, kit supplied complete with rings, pin and clips.

When should you replace the piston?

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

Recommended hours for a top-end rebuild (manufacturer recommendation for the KTM EXC-F, Husqvarna FE 2017-2023):

• Racing: every 70 h.
• Leisure: every 135 h.
• KTM SX-F, Husqvarna FC 2016-2022: racing: every 50 h.

Specifications and fitting tips

• Material: Aluminium
• Specificity: Double Bridge Forging / 3D Shaped Crown / Gas Ported
• Piston compression: Standard
• Piston type: Forged
• Rings Quantity: 2
• Forged piston

Available in several sizes: choose the one that matches your cylinder (stamped size or measured bore). Diameters: A = 87.96 mm, C = 87.98 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 : PROX · ATHENA
• Spark plug : NGK 97225 · NGK 93188
• 4-stroke engine oil : MOTUL 10W50 · LIQUI MOLY 10W40 1 L
• Air filter : HIFLO FILTRO · TWIN AIR

Compatibility

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

Fits:
GAS GAS ECF 350 2023
GAS GAS ECF 350 2022
GAS GAS ECF 350 2021
GAS GAS MCF 350 2023
GAS GAS MCF 350 2022
HUSQVARNA FE 350 2023
HUSQVARNA FE 350 2022
HUSQVARNA FE 350 2021
HUSQVARNA FE 350 2020
KTM EXC-F 350 WESS 2023
KTM EXCF 350 2023
KTM EXCF 350 2022
KTM EXCF 350 2021
KTM EXCF 350 2020