The NAMURA NA-10027-4K Top End Kit is a complete 69.45 mm, +1.00 mm overbore replacement kit designed for select Honda ATV applications. With an 11:1 compression ratio, this kit is engineered to restore top-end performance and provide dependable service when rebuilding a worn or damaged cylinder assembly. The kit includes a piston, piston rings, wrist pin, retaining clips, top-end bearing, and gasket kit for a convenient installation.
Fitment: This NAMURA top-end kit fits 2001–2008 Honda TRX250EX Sportrax models and 2002–2003 Honda TRX250TE Recon ES [SRA] models. Verify the existing cylinder condition, required overbore, compression ratio, and engine specifications before installation to ensure proper compatibility. The +1.00 mm piston size is intended for a properly machined cylinder bore.
Feature: The MOS2, or Teflon/molybdenum, coated piston skirts use a rolled-on application process designed to create a stronger bond than spray-on coatings. This coating helps improve heat transfer, reduce friction, and minimize the possibility of cold seizures. Feature: Machined smooth piston heads help reflect combustion heat and reduce carbon buildup, supporting piston protection and consistent engine operation. Feature: Anodized domes improve heat resistance and durability, while the hypereutectic casting process provides increased silicon content for reduced expansion, improved wear resistance, and greater tolerance of elevated cylinder temperatures.
Features:
- Complete top-end kit includes piston, rings, wrist pin, retaining clips, top-end bearing, and gasket kit
- 69.45 mm piston size with +1.00 mm overbore and 11:1 compression ratio
- MOS2 Teflon/molybdenum coated skirts help reduce friction, improve heat transfer, and minimize cold-seizure risk
- Machined smooth piston head helps reflect combustion heat and reduce carbon buildup
- Anodized dome improves heat resistance and durability
- Hypereutectic casting process provides reduced expansion and increased wear resistance
- Fits 2001–2008 Honda TRX250EX Sportrax and 2002–2003 Honda TRX250TE Recon ES [SRA]
Fitment:
2001 Honda TRX250EX Sportrax
2002 Honda TRX250EX Sportrax
2002 Honda TRX250TE Recon ES [SRA]
2002 Honda TRX250TM Recon [SRA]
2003 Honda TRX250EX Sportrax
2003 Honda TRX250TE Recon ES [SRA]
2003 Honda TRX250TM Recon [SRA]
2004 Honda TRX250EX Sportrax
2004 Honda TRX250TE Recon ES [SRA]
2004 Honda TRX250TM Recon [SRA]
2005 Honda TRX250EX Sportrax
2005 Honda TRX250TE Recon ES [SRA]
2005 Honda TRX250TM Recon [SRA]
2006 Honda TRX250EX Sportrax
2006 Honda TRX250TE Recon ES [SRA]
2006 Honda TRX250TM Recon [SRA]
2007 Honda TRX250EX Sportrax
2007 Honda TRX250TE Recon ES [SRA]
2007 Honda TRX250TM Recon [SRA]
2008 Honda TRX250EX Sportrax
2008 Honda TRX250TE Recon ES [SRA]
2008 Honda TRX250TM Recon [SRA]
2009 Honda TRX250TE Recon ES [SRA]
2009 Honda TRX250TM Recon [SRA]
2009 Honda TRX250X [SRA]
2010 Honda TRX250TE Recon ES [SRA]
2011 Honda TRX250TE Recon ES [SRA]
2011 Honda TRX250TM Recon [SRA]
2011 Honda TRX250X [SRA]
2012 Honda TRX250TE Recon ES [SRA]
2012 Honda TRX250TM Recon [SRA]
2012 Honda TRX250X [SRA]
2013 Honda TRX250TE Recon ES [SRA]
2013 Honda TRX250TM Recon [SRA]
2013 Honda TRX250X [SRA]
2014 Honda TRX250TE Recon ES [SRA]
2014 Honda TRX250TM Recon [SRA]
2014 Honda TRX250X [SRA]
2016 Honda TRX250TE Recon ES [SRA]
2016 Honda TRX250TM Recon [SRA]
2016 Honda TRX250X [SRA]
2017 Honda TRX250TE Recon ES [SRA]
2017 Honda TRX250TM Recon [SRA]
2017 Honda TRX250X [SRA]
2018 Honda TRX250TE Recon ES [SRA]
2018 Honda TRX250TM Recon [SRA]
2018 Honda TRX250X [SRA]
2023 Honda TRX250TE Recon ES [SRA]
2023 Honda TRX250TM Recon [SRA]
2023 Honda TRX250X [SRA]