VERTEX piston kit for KTM EXC-F 350, SX-F 350, HUSQVARNA FC 350, FE 350 and GAS GAS EC 350 F, MC 350 F from 2023 to 2027

VERTEX offers this piston kit for KTM EXC-F 350, SX-F 350, HUSQVARNA FC 350, FE 350 and GAS GAS EC 350 F, MC 350 F from 2023 to 2027. 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?

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 SX-F, Husqvarna FC, GASGAS MC-F since 2023):

• Racing: every 45 h.
• Leisure: no KTM figure; Cross-Mania guideline: compression check at around 90 h.
• KTM EXC-F, Husqvarna FE, GASGAS EC-F since 2024: racing and leisure: every 90 h.

Specifications and fitting tips

• Displacement: 350 cm³
• Piston material: Aluminium alloy, Forged
• Ring material: Nitride coating, Steel
• Skirt coating: Molybdenum coating
• Style: Forged Replica
• Pro Replica: forged piston matching the original OE shape

Available in several sizes: choose the one that matches your cylinder (stamped size or measured bore). Diameters: A = 87.96 mm, B = 87.97 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 : MOOSE 817977MSE · MOOSE 819049MSE
• Spark plug : NGK 97225 · NGK 93188
• 4-stroke engine oil : LIQUI MOLY 10W40 1 L · MOTUL 10W50
• Air filter : TECNIUM · HIFLO FILTRO

Compatibility

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

Fits:
GAS GAS EC 350 F 2026
GAS GAS EC 350 F 2025
GAS GAS EC 350 F 2024
GAS GAS MC 350 F 2025
GAS GAS MC 350 F 2024
HUSQVARNA FC 350 2027
HUSQVARNA FC 350 2026
HUSQVARNA FC 350 2025
HUSQVARNA FC 350 2024
HUSQVARNA FC 350 2023
HUSQVARNA FE 350 2025
HUSQVARNA FE 350 2024
KTM EXC-F 350 2027
KTM EXC-F 350 2026
KTM EXC-F 350 2025
KTM EXC-F 350 2024
KTM SX-F 350 2027
KTM SX-F 350 2026
KTM SX-F 350 2025
KTM SX-F 350 2024
KTM SX-F 350 2023