ATHENA Piston Pin Circlips Ø12 mm for RIEJU MRT 50, RR 50, BETA RR 50, APRILIA MX 50, PEGASO 50, RX 50 and HM CRE 50 1992-2024

The ATHENA Ø12 mm S410000304002 set of piston pin circlips is designed for APRILIA MX 50, PEGASO 50, RX 50, RIEJU MRT 50, RR 50, BETA RR 50 and HM CRE 50 from 1992 to 2024. Piston pin circlips hold the pin in place inside the piston. If one comes out of its groove, the pin scores the cylinder and the engine is wrecked. These small parts cost next to nothing but must never be reused.

Specifications

• Brand: ATHENA
• Manufacturer part number: S410000304002
• EAN code: 8051757105021
• For ATHENA piston
• Engine: 2-stroke

When to replace it?

• Circlip distorted, opened up or marked on teardown.
• Circlip already removed once: it has lost its tension.
• Wear marks in the piston groove.

Every time the piston pin is removed: a circlip that has been taken out is always replaced with a new one.

Fitting tips

1. Check that the circlip size matches your piston pin (see specifications).
2. Plug the crankcase opening with a rag before fitting the circlips: one dropped into the engine means a full strip-down.
3. Fit each circlip without distorting it, gap opposite the notch in the piston, and check it sits all the way round its groove.

Why ATHENA?

Athena, an Italian company founded in 1973 near Vicenza, designs gaskets, pistons and cylinder kits for motorcycles. An OEM supplier to KTM, Ducati, Fantic, Piaggio and Triumph and a partner of the MXGP world championship, it develops its parts on the test bench and on the track with racing teams.

Spare parts and items to plan

• ATHENA cylinder kit : ATHENA
• Piston : ATHENA
• Cylinder head and dome : ATHENA S410105308003 · ATHENA S410130308003

Frequently asked questions

How many circlips do I need?
Two per piston, one on each side of the pin. Check the quantity stated for the part number.

Can I reuse the old circlips?
No: a circlip that has been removed loses its tension and may come out of its groove. Always fit new ones.

Compatibility

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

Fits:
APRILIA MX 50 2004
APRILIA MX 50 2003
APRILIA MX 50 2002
APRILIA PEGASO 50 1997
APRILIA PEGASO 50 1996
APRILIA PEGASO 50 1995
APRILIA PEGASO 50 1994
APRILIA PEGASO 50 1993
APRILIA PEGASO 50 1992
APRILIA RX 50 2004
APRILIA RX 50 2003
APRILIA RX 50 2002
APRILIA RX 50 2001
APRILIA RX 50 2000
APRILIA RX 50 1999
APRILIA RX 50 1998
APRILIA RX 50 1997
APRILIA RX 50 1996
APRILIA RX 50 1995
BETA RR 50 2024
BETA RR 50 2023
BETA RR 50 2022
BETA RR 50 2021
BETA RR 50 2020
BETA RR 50 2019
BETA RR 50 2018
BETA RR 50 2017
BETA RR 50 2016
BETA RR 50 2015
BETA RR 50 2014
BETA RR 50 2013
BETA RR 50 2012
BETA RR 50 2011
BETA RR 50 2010
BETA RR 50 2009
BETA RR 50 2008
BETA RR 50 2007
BETA RR 50 2006
BETA RR 50 2005
BETA RR 50 2004
BETA RR 50 2003
BETA RR 50 2002
BETA RR 50 2001
BETA RR 50 2000
BETA RR 50 1999
BETA RR 50 1998
HM CRE 50 2017
HM CRE 50 2016
HM CRE 50 2015
HM CRE 50 2014
HM CRE 50 2013
HM CRE 50 2012
HM CRE 50 2011
HM CRE 50 2010
HM CRE 50 2009
HM CRE 50 2008
HM CRE 50 2007
HM CRE 50 2006
HM CRE 50 2005
HM CRE 50 2004
HM CRE 50 2003
HM CRE 50 2002
HM CRE 50 2001
HM CRE 50 2000
HM CRE 50 1999
RIEJU MRT 50 2024
RIEJU MRT 50 2023
RIEJU MRT 50 2022
RIEJU MRT 50 2021
RIEJU MRT 50 2020
RIEJU MRT 50 2019
RIEJU MRT 50 2018
RIEJU MRT 50 2017
RIEJU MRT 50 2016
RIEJU MRT 50 2015
RIEJU MRT 50 2014
RIEJU MRT 50 2013
RIEJU MRT 50 2012
RIEJU MRT 50 2011
RIEJU MRT 50 2010
RIEJU MRT 50 2009
RIEJU RR 50 2008
RIEJU RR 50 2007
RIEJU RR 50 2006
RIEJU RR 50 2005
RIEJU RR 50 2004
RIEJU RR 50 2003
RIEJU RR 50 2002
RIEJU RR 50 2001
RIEJU RR 50 2000
RIEJU RR 50 1999
RIEJU RR 50 1998
RIEJU RR 50 1997
RIEJU RR 50 1996
RIEJU RR 50 1995
RIEJU RR 50 1994
RIEJU RR 50 1993