METEOR Piston Kit ref. 2704MC for GAS GAS TXT 300 and SHERCO ST 300 2002-2022

On GAS GAS TXT 300 and SHERCO ST 300 from 2002 to 2022, the METEOR 2704MC piston kit (Ø 78.97 mm) fits in place of the original part. At the heart of the top end, the piston soaks up the heat and pressure of every explosion. As it wears, the rings no longer seal against the cylinder: compression drops, power drops with it, and the risk of seizure goes up.

Key features

• Italian piston manufacturer since 1952.
• Complete kit: piston, ring(s), pin and circlips.

Specifications

• Brand: METEOR
• Manufacturer part number: 2704MC
• Compression height: 28.7 mm
• Piston pin diameter: 18 mm
• Rings: 2 x 1.2 mm
• Piston diameter: 78.97 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 METEOR?

Meteor is an Italian piston manufacturer founded in 1952. Formerly an OEM supplier to Piaggio and Innocenti, the brand now develops pistons for motocross and enduro through its Meteor Racing division.

Spare parts and items to plan

• Piston rings : see the selection
• Piston pin : WOSSNER
• Top-end gasket kit : CENTAURO · ATHENA
• Small end needle bearing : see the selection
• Spark plug : NGK 6597 · NGK 7422
• Coolant : LIQUI MOLY 1 L · TWIN AIR
• 2-stroke oil : LIQUI MOLY 1 L · LIQUI MOLY 4 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 TXT 300 2022
GAS GAS TXT 300 2021
GAS GAS TXT 300 2020
GAS GAS TXT 300 2019
GAS GAS TXT 300 2018
GAS GAS TXT 300 2017
GAS GAS TXT 300 2016
GAS GAS TXT 300 2015
GAS GAS TXT 300 2014
GAS GAS TXT 300 2013
GAS GAS TXT 300 2012
GAS GAS TXT 300 2011
GAS GAS TXT 300 2010
GAS GAS TXT 300 2009
GAS GAS TXT 300 2008
GAS GAS TXT 300 2007
GAS GAS TXT 300 2006
GAS GAS TXT 300 2005
GAS GAS TXT 300 2004
GAS GAS TXT 300 2003
GAS GAS TXT 300 2002
SHERCO ST 300 2022
SHERCO ST 300 2021
SHERCO ST 300 2020
SHERCO ST 300 2019
SHERCO ST 300 2018
SHERCO ST 300 2017
SHERCO ST 300 2016
SHERCO ST 300 2015
SHERCO ST 300 2014