The Namura NA-40011-4 Piston Kit is designed for select Yamaha 450 engines and provides a reliable replacement piston solution for powersports applications. This oversized 85.45 mm piston kit is intended for use with a cylinder that has been properly machined to match the piston specification. The kit is manufactured by Namura and is identified by manufacturer part number NA-40011-4.
This piston kit fits 2006–2009 Yamaha YXR450F Rhino 450 models and 2007–2008 Yamaha YFM450FG Grizzly 4WD [IRS] models, as well as 2011–2014 Yamaha YFM450FGP Grizzly 4WD EPS [IRS] models. Confirm the exact year, model, engine configuration, and cylinder specifications before installation to ensure proper compatibility.
Important Fitment Note: The Namura NA-40011-4 piston will not accept OEM rings, and its rings will not work with an OEM piston. Use the ring set specified for this Namura piston and follow the applicable installation, clearance, and break-in procedures. This product is supplied as a piston kit for compatible Yamaha applications; verify included components and installation requirements before rebuilding the engine.
Features:
- Brand: Namura
- Manufacturer Part Number: NA-40011-4
- Vendor Part Number: NA-40011-4
- Piston Size: 85.45 mm, +1.00 mm oversize
- Application: Yamaha 450 powersports engines
- Fitment: 2006–2009 Yamaha YXR450F Rhino 450
- Fitment: 2007–2008 Yamaha YFM450FG Grizzly 4WD [IRS]
- Fitment: 2011–2014 Yamaha YFM450FGP Grizzly 4WD EPS [IRS]
- Compatibility Note: Does not accept OEM rings, and the supplied rings are not compatible with an OEM piston
Fitment:
2003 Yamaha YFM450FA Kodiak 4WD [IRS]
2004 Yamaha YFM450FA Kodiak 4WD [IRS]
2005 Yamaha YFM450FA Kodiak 4WD [IRS]
2006 Yamaha YFM450FA Kodiak 4WD [IRS]
2006 Yamaha YFM450FX Wolverine 4WD [SRA]
2006 Yamaha YXR450F Rhino 450
2007 Yamaha YFM450FG Grizzly 4WD [IRS]
2007 Yamaha YFM450FX Wolverine 4WD [SRA]
2007 Yamaha YXR450F Rhino 450
2008 Yamaha YFM450FG Grizzly 4WD [IRS]
2008 Yamaha YFM450FX Wolverine 4WD [SRA]
2008 Yamaha YXR450F Rhino 450
2009 Yamaha YFM450FG Grizzly 4WD [IRS]
2009 Yamaha YFM450FX Wolverine 4WD [SRA]
2009 Yamaha YXR450F Rhino 450
2010 Yamaha YFM450FG Grizzly 4WD [IRS]
2010 Yamaha YFM450FX Wolverine 4WD [SRA]
2011 Yamaha YFM450FG Grizzly 4WD [IRS]
2011 Yamaha YFM450FGP Grizzly 4WD EPS [IRS]
2012 Yamaha YFM450FG Grizzly 4WD [IRS]
2012 Yamaha YFM450FGP Grizzly 4WD EPS [IRS]
2013 Yamaha YFM450FG Grizzly 4WD [IRS]
2013 Yamaha YFM450FGP Grizzly 4WD EPS [IRS]
2014 Yamaha YFM450FG Grizzly 4WD [IRS]
2014 Yamaha YFM450FGP Grizzly 4WD EPS [IRS]
2018 Yamaha YFM450FA Kodiak 4WD [IRS]
2019 Yamaha YFM450FA Kodiak 4WD [IRS]
2020 Yamaha YFM450FA Kodiak 4WD [IRS]