WÖSSNER Piston Kit for HUSQVARNA TE 300, KTM EXC 300 and GAS GAS EC 300 2018-2025

The WÖSSNER 8327DC piston kit (Ø 71.96 mm) is designed for KTM EXC 300, HUSQVARNA TE 300 and GAS GAS EC 300 from 2018 to 2025. The piston takes the pressure of every combustion and passes it on to the connecting rod, thousands of times a minute. Over the hours it wears, its rings stop sealing properly and the engine loses compression: it starts less easily, pulls less hard and runs hotter.

Key features

• Forged piston in T6 heat-treated 4032 alloy, designed using computer simulation (FEA).
• Permanent skirt coating that reduces friction.
• Very tight running clearance, for a quieter engine (according to Wössner).
• Complete kit: piston, rings, pin and circlips. Small-end needle bearing not included.

Specifications

• Brand: WÖSSNER
• Manufacturer part number: 8327DC
• Size: C (check that it matches your cylinder)
• Piston diameter: 71.96 mm
• Engine: 2-stroke

When to replace it?

• Loss of power, sluggish pick-up, harder starting: compression is dropping.
• Piston slap on a cold engine, getting more and more noticeable.
• On teardown: vertical scoring on the skirt, stuck or worn rings, thick carbon on the crown.

Replace the piston as set out in your bike's service manual, sooner if you race, and straight away as soon as these symptoms appear. As a Cross-Mania guideline, plan for a new piston every 20 to 40 hours of engine running depending on whether you race or ride for fun. Always measure the cylinder at the same time: a new piston in an oval cylinder won't last.

Fitting tips

1. Clean the cylinder and check it: diameter, ovality, taper and condition of the bore coating.
2. Check the end gap of each ring in the cylinder against the figures in the manual or the manufacturer's instructions.
3. Fit the rings with the mark facing up and each gap correctly located on its locating pin.
4. Check the small-end needle bearing and the pin: at the slightest play, tight spot or marked needle, replace the bearing.
5. Fit the piston with its arrow pointing to the exhaust side, oil the pin and the small end, then fit the circlips without distorting them, gap opposite the notch. A circlip that has been taken out is replaced with new piston pin circlips, never refitted.
6. Reassemble with a new top end gasket kit and tighten the cylinder head in a criss-cross pattern to the manufacturer's torque.
7. Refill the coolant and fit a new spark plug.
8. Break the engine in: warm it up gently, vary the revs and avoid sustained full throttle for the first hour.

Why WÖSSNER?

A German brand created by former racer Eckart Wössner, Wössner has been designing and forging its own pistons since 1994. These pistons are built for racing and are now used by Supercross, Arenacross and MXGP teams.

Spare parts and items to plan

• Piston rings : ATHENA · WOSSNER
• Piston pin : WOSSNER CW18 · WOSSNER WP033
• Piston pin clips : WISECO · VERTEX
• Top-end gasket kit : VHM SK33000.VITON · VHM SK33000
• Small end needle bearing : PROX · ATHENA
• Spark plug : NGK 5122 · NGK 6664
• Coolant : LIQUI MOLY 1 L · TWIN AIR
• 2-stroke oil : LIQUI MOLY 1 L · MOTUL 1 L

Frequently asked questions

Does the kit include the gaskets?
No: the kit contains the piston, rings, pin and circlips. Add a top end gasket kit, because a head or base gasket can never be reused.

Can I replace just the rings later?
Yes, as long as the piston and cylinder are still within tolerance. Replacement rings can be ordered on their own, as can the piston pin and the circlips.

Should I replace the small-end needle bearing?
It isn't included. Check it at every piston change and replace the needle bearing at the slightest play or tight spot.

Compatibility

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

Fits:
GAS GAS EC 300 2025
GAS GAS EC 300 2024
GAS GAS EC 300 2023
GAS GAS EC 300 2022
GAS GAS EC 300 2021
HUSQVARNA TE 300 2025
HUSQVARNA TE 300 2024
HUSQVARNA TE 300 2023
HUSQVARNA TE 300 2022
HUSQVARNA TE 300 2021
HUSQVARNA TE 300 2020
HUSQVARNA TE 300 2019
HUSQVARNA TE 300 2018
KTM EXC 300 2025
KTM EXC 300 2024
KTM EXC 300 2023
KTM EXC 300 2022
KTM EXC 300 2021
KTM EXC 300 2020
KTM EXC 300 2019
KTM EXC 300 2018