Spare Part KAYABA Piston Ring for BETA RX 300, RX 450, GAS GAS EC 250, EC 300, RIEJU MR 250, MR 300 and YAMAHA YZ 250 X

KAYABA offers this piston kit for BETA RR 125, RR 200, RR 250, RX 300, RX 450, GAS GAS EC 250, EC 300, XC 250, XC 300, RIEJU MR 250, MR 300 and YAMAHA YZ 250 X 2016-2027. The piston slides in the cylinder and takes the force of the air-fuel combustion, passing it to the connecting rod and crankshaft.

Forged or cast piston?

• Forged: hot-pressed then machined aluminium, stronger when hot and lighter for the same strength; sometimes fitted with a little more clearance, and costs more.
• Cast: aluminium poured into a mould, like most OEM pistons; it expands little, runs quietly and costs less, but tolerates overheating less well.
• In short: forged for racing or a tuned engine, cast for a stock engine used for leisure riding.

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 Beta RR four-stroke):

• Normal use: every 90 h.
• Racing: no Beta figure; Cross-Mania guideline: compression check at around 45 h.
• Yamaha YZ 250 two-stroke: racing: every 12.5 h (about 5 races).

Specifications and fitting tips

• Manufacturer part number: 120214600501

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 · TECNIUM
• Spark plug : see the selection
• 2-stroke oil : LIQUI MOLY 1 L 3065 · LIQUI MOLY 1 L 3063
• Air filter : TWIN AIR over-filter for GAS GAS EC, E… · TECNIUM

Compatibility

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

Fits:
BETA RR 125 2024
BETA RR 125 2023
BETA RR 125 2T RACE 2025
BETA RR 125 2T X-PRO 2025
BETA RR 200 2024
BETA RR 200 2023
BETA RR 200 2T RACE 2025
BETA RR 200 2T X-PRO 2025
BETA RR 250 2024
BETA RR 250 2023
BETA RR 250 2T RACE 2025
BETA RR 250 2T X-PRO 2025
BETA RR 300 2024
BETA RR 300 2023
BETA RR 300 2T RACE 2025
BETA RR 300 2T X-PRO 2025
BETA RR 350 2024
BETA RR 350 2023
BETA RR 350 4T RACE 2025
BETA RR 350 4T X-PRO 2025
BETA RR 390 2024
BETA RR 390 2023
BETA RR 390 4T RACE 2025
BETA RR 390 4T X-PRO 2025
BETA RR 430 2024
BETA RR 430 2023
BETA RR 430 4T RACE 2025
BETA RR 430 4T X-PRO 2025
BETA RR 480 2024
BETA RR 480 2023
BETA RR 480 4T RACE 2025
BETA RR 480 4T X-PRO 2025
BETA RX 300 2026
BETA RX 300 2025
BETA RX 300 2024
BETA RX 300 2023
BETA RX 300 2022
BETA RX 300 2021
BETA RX 450 2027
BETA RX 450 2026
BETA RX 450 2025
BETA RX 450 2024
GAS GAS EC 250 2020
GAS GAS EC 250 2019
GAS GAS EC 250 2018
GAS GAS EC 300 2020
GAS GAS EC 300 2019
GAS GAS EC 300 2018
GAS GAS XC 250 2020
GAS GAS XC 250 2019
GAS GAS XC 250 2018
GAS GAS XC 300 2020
GAS GAS XC 300 2019
GAS GAS XC 300 2018
RIEJU MR 250 2024
RIEJU MR 250 2023
RIEJU MR 250 2022
RIEJU MR 250 2021
RIEJU MR 300 2026
RIEJU MR 300 2024
RIEJU MR 300 2023
RIEJU MR 300 2022
RIEJU MR 300 2021
RIEJU MR 300 2020
YAMAHA YZ 250 X 2024
YAMAHA YZ 250 X 2023
YAMAHA YZ 250 X 2022
YAMAHA YZ 250 X 2021
YAMAHA YZ 250 X 2020
YAMAHA YZ 250 X 2019
YAMAHA YZ 250 X 2018
YAMAHA YZ 250 X 2017
YAMAHA YZ 250 X 2016