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Namura Piston Assembly - 84mm Bore - NA-40005-4

  • Part #: 1331924
  • Manufacturer Part #: NA-40005-4

MSRP Price: $91.05

Our Price: $81.94

You Save:
$9.11 (10%)
2 on Hand

Overview of Namura Piston Assembly - 84mm Bore - NA-40005-4

  • High-performance Namura pistons are engineered in the USA, manufactured in Taiwan
  • High-silicon content Hypereutectic cast aluminum material for less heat expansion, tighter clearances, increased hardness, longer life and reduced scuffing
  • Features machined, smooth piston crowns for reduced carbon buildup, increased horsepower and fuel economy
  • Hard anodized crowns are 75% stronger than non-anodized, providing minimal expansion and reducing the chance of cold seizures when combined with Teflon/Molybdenum coated skirts
  • MOS2 (Teflon/Molybdenum) coated skirts perform at the highest standards, reducing friction and heat for added power and longevity
  • Namura rings match the OEM design except as noted
  • -B (.0004 in.) and -C (.0008 in.) fractional oversize pistons, available for some applications, extend the life of your expensive cylinder by renewing the original clearance if it's slightly worn, avoiding an expensive sleeve installation
  • Piston assemblies include ring(s), wrist pin and circlips


  • Included Items:
    (1) Pison
    (1) Ring set
    (2) Wrist pin clips
    (1) Wrist pin

Specs for Namura Piston Assembly - 84mm Bore - NA-40005-4

Bore Size 84 mm
Type Piston Assembly
Type - Pistons & Piston Rings Piston w/Ring Set
Units Each
Weight 1.05 lbs

Specs for Namura Piston Assembly - 84mm Bore - NA-40005-4

Bore Size 84 mm
Type Piston Assembly
Type - Pistons & Piston Rings Piston w/Ring Set
Units Each
Weight 1.05 lbs

Fitment for Namura Piston Assembly - 84mm Bore - NA-40005-4

See if this part fits your ride

Part 1331924 fits the following machines

Yamaha
  • 1988 Yamaha BW350 Big Wheel
  • 1987 Yamaha BW350 Big Wheel
  • 2004 Yamaha YFM350 Raptor
  • 2006 Yamaha YFM350BA Bruin 2x4
  • 2005 Yamaha YFM350BA Bruin 2x4
  • 2004 Yamaha YFM350BA Bruin 2x4
  • 1995 Yamaha YFM350ER Moto 4
  • 1994 Yamaha YFM350ER Moto 4
  • 1993 Yamaha YFM350ER Moto 4
  • 1992 Yamaha YFM350ER Moto 4
  • 1990 Yamaha YFM350ER Moto 4
  • 1989 Yamaha YFM350ER Moto 4
  • 1988 Yamaha YFM350ER Moto 4
  • 1987 Yamaha YFM350ER Moto 4
  • 2006 Yamaha YFM350FA Bruin 4x4
  • 2005 Yamaha YFM350FA Bruin 4x4
  • 2004 Yamaha YFM350FA Bruin 4x4
  • 2006 Yamaha YFM350FAH Bruin 4x4 Hunter Edition
  • 2005 Yamaha YFM350FAH Bruin 4x4 Hunter Edition
  • 2004 Yamaha YFM350FAH Bruin 4x4 Hunter Edition
  • 2014 Yamaha YFM350FG Grizzly 4x4
  • 2013 Yamaha YFM350FG Grizzly 4x4
  • 2012 Yamaha YFM350FG Grizzly 4x4
  • 2011 Yamaha YFM350FG Grizzly 4x4
  • 2010 Yamaha YFM350FG Grizzly 4x4
  • 2009 Yamaha YFM350FG Grizzly 4x4
  • 2008 Yamaha YFM350FG Grizzly 4x4
  • 2007 Yamaha YFM350FG Grizzly 4x4
  • 2014 Yamaha YFM350FGH Grizzly 4x4 Hunter Edition
  • 2013 Yamaha YFM350FGH Grizzly 4x4 Hunter Edition
  • 2012 Yamaha YFM350FGH Grizzly 4x4 Hunter Edition
  • 2011 Yamaha YFM350FGH Grizzly 4x4 Hunter Edition
  • 2010 Yamaha YFM350FGH Grizzly 4x4 Hunter Edition
  • 2009 Yamaha YFM350FGH Grizzly 4x4 Hunter Edition
  • 2008 Yamaha YFM350FGH Grizzly 4x4 Hunter Edition
  • 2011 Yamaha YFM350FGI Grizzly 4x4 IRS
  • 2010 Yamaha YFM350FGI Grizzly 4x4 IRS
  • 2009 Yamaha YFM350FGI Grizzly 4x4 IRS
  • 2008 Yamaha YFM350FGI Grizzly 4x4 IRS
  • 2007 Yamaha YFM350FGI Grizzly 4x4 IRS
  • 2011 Yamaha YFM350FGIH Grizzly 4x4 IRS Hunter Edition
  • 2010 Yamaha YFM350FGIH Grizzly 4x4 IRS Hunter Edition
  • 2009 Yamaha YFM350FGIH Grizzly 4x4 IRS Hunter Edition
  • 2008 Yamaha YFM350FGIH Grizzly 4x4 IRS Hunter Edition
  • 2007 Yamaha YFM350FGIH Grizzly 4x4 IRS Hunter Edition
  • 1999 Yamaha YFM350FH Big Bear 4x4 Hunter Edition
  • 1996 Yamaha YFM350FW Big Bear 4x4
  • 1995 Yamaha YFM350FW Big Bear 4x4
  • 1994 Yamaha YFM350FW Big Bear 4x4
  • 1993 Yamaha YFM350FW Big Bear 4x4
  • 1992 Yamaha YFM350FW Big Bear 4x4
  • 1991 Yamaha YFM350FW Big Bear 4x4
  • 1990 Yamaha YFM350FW Big Bear 4x4
  • 1989 Yamaha YFM350FW Big Bear 4x4
  • 1988 Yamaha YFM350FW Big Bear 4x4
  • 1987 Yamaha YFM350FW Big Bear 4x4
  • 1997 Yamaha YFM350FW Big Bear 4x4 SE
  • 1999 Yamaha YFM350FWB Big Bear 4x4
  • 1998 Yamaha YFM350FWB Big Bear 4x4
  • 1997 Yamaha YFM350FWB Big Bear 4x4
  • 2005 Yamaha YFM350FX Wolverine 4x4
  • 2004 Yamaha YFM350FX Wolverine 4x4
  • 2003 Yamaha YFM350FX Wolverine 4x4
  • 2002 Yamaha YFM350FX Wolverine 4x4
  • 2001 Yamaha YFM350FX Wolverine 4x4
  • 2000 Yamaha YFM350FX Wolverine 4x4
  • 1999 Yamaha YFM350FX Wolverine 4x4
  • 1998 Yamaha YFM350FX Wolverine 4x4
  • 1997 Yamaha YFM350FX Wolverine 4x4
  • 1996 Yamaha YFM350FX Wolverine 4x4
  • 1995 Yamaha YFM350FX Wolverine 4x4
  • 2011 Yamaha YFM350G Grizzly
  • 2010 Yamaha YFM350G Grizzly
  • 2009 Yamaha YFM350G Grizzly
  • 2008 Yamaha YFM350G Grizzly
  • 2007 Yamaha YFM350G Grizzly
  • 2013 Yamaha YFM350R Raptor
  • 2012 Yamaha YFM350R Raptor
  • 2011 Yamaha YFM350R Raptor
  • 2010 Yamaha YFM350R Raptor
  • 2009 Yamaha YFM350R Raptor
  • 2008 Yamaha YFM350R Raptor
  • 2007 Yamaha YFM350R Raptor
  • 2006 Yamaha YFM350R Raptor
  • 2005 Yamaha YFM350R Raptor
  • 2007 Yamaha YFM350RSE Raptor Special Edition
  • 2006 Yamaha YFM350RSE Raptor Special Edition
  • 2005 Yamaha YFM350RSE Raptor Special Edition
  • 2007 Yamaha YFM350RSE2 Raptor Special Edition 2
  • 1999 Yamaha YFM350U Big Bear 2x4
  • 1998 Yamaha YFM350U Big Bear 2x4
  • 1997 Yamaha YFM350U Big Bear 2x4
  • 1996 Yamaha YFM350U Big Bear 2x4
  • 2004 Yamaha YFM350X Warrior
  • 2003 Yamaha YFM350X Warrior
  • 2002 Yamaha YFM350X Warrior
  • 2001 Yamaha YFM350X Warrior
  • 2000 Yamaha YFM350X Warrior
  • 1999 Yamaha YFM350X Warrior
  • 1998 Yamaha YFM350X Warrior
  • 1997 Yamaha YFM350X Warrior
  • 1996 Yamaha YFM350X Warrior
  • 1995 Yamaha YFM350X Warrior
  • 1994 Yamaha YFM350X Warrior
  • 1993 Yamaha YFM350X Warrior
  • 1992 Yamaha YFM350X Warrior
  • 1991 Yamaha YFM350X Warrior
  • 1990 Yamaha YFM350X Warrior
  • 1989 Yamaha YFM350X Warrior
  • 1988 Yamaha YFM350X Warrior
  • 1987 Yamaha YFM350X Warrior
  • 2009 Yamaha YFM350X Wolverine 2x4
  • 2008 Yamaha YFM350X Wolverine 2x4
  • 2007 Yamaha YFM350X Wolverine 2x4
  • 2006 Yamaha YFM350X Wolverine 2x4
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Instructions and Manuals for Namura Piston Assembly - 84mm Bore - NA-40005-4