Restore dependable top-end performance with the Namura NA-10043-1K Top End Kit. Designed for select Honda Rancher 420 AT and ES models, this kit includes the piston, piston rings, wrist pin, retaining clips, top-end bearing, and gasket kit needed for a complete upper-engine rebuild. The piston is manufactured for an 11:1 compression ratio and an 86.73 mm +0.25 oversize application, providing a precise replacement solution for engines requiring a rebore.
The Namura piston features MOS2, or Teflon and molybdenum, coated skirts. This rolled-on coating process creates a strong bond that helps reduce friction, improve heat transfer, and minimize the risk of cold seizures. Machined smooth heads help reflect combustion heat and reduce carbon buildup, helping protect the piston crown while supporting consistent engine operation.
An anodized dome increases heat resistance and durability, while the hypereutectic casting process provides increased silicon content for controlled expansion and improved wear resistance. These features help the piston withstand higher cylinder temperatures and demanding riding conditions. The kit is intended for compatible 2014–2017 Honda TRX420FA and 2014–2016 Honda TRX420FE applications, including Rancher 4x4 AT DCT, AT DCT EPS, and ES models with SRA. Verify the exact model designation and engine requirements before installation.
Manufacturer: Namura. Vendor part number: NA-10043-1K.
Features:
- Complete top-end kit includes piston, rings, wrist pin, retaining clips, top-end bearing, and gasket kit
- 86.73 mm +0.25 oversize piston designed for an 11:1 compression ratio
- MOS2 Teflon and 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 piston durability
- Hypereutectic casting process provides controlled expansion and increased wear resistance
- Fits select 2014–2017 Honda TRX420FA Rancher 4x4 AT DCT and AT DCT EPS models
- Fits select 2014–2016 Honda TRX420FE Rancher 4x4 ES models
- Brand: Namura
- Manufacturer part number: NA-10043-1K
- Vendor part number: NA-10043-1K
Fitment:
2009 Honda TRX420FA Rancher AT [IRS]
2009 Honda TRX420FE Rancher ES [SRA]
2009 Honda TRX420FM Rancher [SRA]
2009 Honda TRX420FPA Rancher w/PS [IRS]
2009 Honda TRX420FPE Rancher ES w/PS [SRA]
2009 Honda TRX420FPM Rancher w/PS [SRA]
2009 Honda TRX420TE Rancher 2x4 ES [SRA]
2009 Honda TRX420TM Rancher [SRA]
2010 Honda TRX420FA Rancher AT [IRS]
2010 Honda TRX420FE Rancher ES [SRA]
2010 Honda TRX420FM Rancher [SRA]
2010 Honda TRX420FPA Rancher w/PS [IRS]
2010 Honda TRX420FPE Rancher ES w/PS [SRA]
2010 Honda TRX420FPM Rancher w/PS [SRA]
2010 Honda TRX420TE Rancher 2x4 ES [SRA]
2010 Honda TRX420TM Rancher [SRA]
2011 Honda TRX420FA Rancher AT [IRS]
2011 Honda TRX420FE Rancher ES [SRA]
2011 Honda TRX420FM Rancher [SRA]
2011 Honda TRX420FPA Rancher w/PS [IRS]
2011 Honda TRX420FPE Rancher ES w/PS [SRA]
2011 Honda TRX420FPM Rancher w/PS [SRA]
2011 Honda TRX420TE Rancher 2x4 ES [SRA]
2011 Honda TRX420TM Rancher [SRA]
2012 Honda TRX420FA Rancher AT [IRS]
2012 Honda TRX420FE Rancher ES [SRA]
2012 Honda TRX420FM Rancher [SRA]
2012 Honda TRX420FPA Rancher w/PS [IRS]
2012 Honda TRX420FPE Rancher ES w/PS [SRA]
2012 Honda TRX420FPM Rancher w/PS [SRA]
2012 Honda TRX420TE Rancher 2x4 ES [SRA]
2012 Honda TRX420TM Rancher [SRA]
2013 Honda TRX420FA Rancher AT [IRS]
2013 Honda TRX420FE Rancher ES [SRA]
2013 Honda TRX420FM Rancher [SRA]
2013 Honda TRX420FPA Rancher w/PS [IRS]
2013 Honda TRX420FPE Rancher ES w/PS [SRA]
2013 Honda TRX420FPM Rancher w/PS [SRA]
2013 Honda TRX420TE Rancher 2x4 ES [SRA]
2013 Honda TRX420TM Rancher [SRA]
2014 Honda TRX420FA Rancher AT [IRS]
2014 Honda TRX420FA1 Rancher 4x4 AT DCT [SRA]
2014 Honda TRX420FA2 Rancher 4x4 AT DCT EPS [SRA]
2014 Honda TRX420FE1 Rancher 4x4 ES [SRA]
2014 Honda TRX420FM1 Rancher 4x4 [SRA]
2014 Honda TRX420FM2 Rancher 4x4 EPS [SRA]
2014 Honda TRX420FPA Rancher w/PS [IRS]
2014 Honda TRX420TE1 Rancher 2x4 ES [SRA]
2014 Honda TRX420TM1 Rancher [SRA]
2015 Honda TRX420FA1 Rancher 4x4 AT DCT [SRA]
2015 Honda TRX420FA2 Rancher 4x4 AT DCT EPS [SRA]
2015 Honda TRX420FA5 Rancher 4x4 AT DCT [IRS]
2015 Honda TRX420FA6 Rancher 4x4 AT DCT EPS [IRS]
2015 Honda TRX420FE1 Rancher 4x4 ES [SRA]
2015 Honda TRX420FM1 Rancher 4x4 [SRA]
2015 Honda TRX420FM2 Rancher 4x4 EPS [SRA]
2015 Honda TRX420TE1 Rancher 2x4 ES [SRA]
2015 Honda TRX420TM1 Rancher [SRA]
2016 Honda TRX420FA1 Rancher 4x4 AT DCT [SRA]
2016 Honda TRX420FA2 Rancher 4x4 AT DCT EPS [SRA]
2016 Honda TRX420FA5 Rancher 4x4 AT DCT [IRS]
2016 Honda TRX420FA6 Rancher 4x4 AT DCT EPS [IRS]
2016 Honda TRX420FE1 Rancher 4x4 ES [SRA]
2016 Honda TRX420FM1 Rancher 4x4 [SRA]
2016 Honda TRX420FM2 Rancher 4x4 EPS [SRA]
2016 Honda TRX420TE1 Rancher 2x4 ES [SRA]
2016 Honda TRX420TM1 Rancher [SRA]
2017 Honda TRX420FA2 Rancher 4x4 AT DCT EPS [SRA]
2017 Honda TRX420FA5 Rancher 4x4 AT DCT [IRS]
2017 Honda TRX420FA6 Rancher 4x4 AT DCT EPS [IRS]
2017 Honda TRX420FE1 Rancher 4x4 ES [SRA]
2017 Honda TRX420FM1 Rancher 4x4 [SRA]
2017 Honda TRX420TM1 Rancher [SRA]
2018 Honda TRX420FA2 Rancher 4x4 AT DCT EPS [SRA]
2018 Honda TRX420FA5 Rancher 4x4 AT DCT [IRS]
2018 Honda TRX420FA6 Rancher 4x4 AT DCT EPS [IRS]
2018 Honda TRX420FE1 Rancher 4x4 ES [SRA]
2018 Honda TRX420FM1 Rancher 4x4 [SRA]
2018 Honda TRX420TM1 Rancher [SRA]
2019 Honda TRX420FA2 Rancher 4x4 AT DCT EPS [SRA]
2019 Honda TRX420FA5 Rancher 4x4 AT DCT [IRS]
2019 Honda TRX420FA6 Rancher 4x4 AT DCT EPS [IRS]
2020 Honda TRX420FA2 Rancher 4x4 AT DCT EPS [SRA]
2020 Honda TRX420FA5 Rancher 4x4 AT DCT [IRS]
2020 Honda TRX420FA6 Rancher 4x4 AT DCT EPS [IRS]
2021 Honda TRX420FA2 Rancher 4x4 AT DCT EPS [SRA]
2021 Honda TRX420FA5 Rancher 4x4 AT DCT [IRS]
2021 Honda TRX420FA6 Rancher 4x4 AT DCT EPS [IRS]
2022 Honda TRX420FA2 Rancher 4x4 AT DCT EPS [SRA]
2022 Honda TRX420FA5 Rancher 4x4 AT DCT [IRS]
2022 Honda TRX420FA6 Rancher 4x4 AT DCT EPS [IRS]
2023 Honda TRX420FA2 Rancher 4x4 AT DCT EPS [SRA]
2023 Honda TRX420FA5 Rancher 4x4 AT DCT [IRS]
2023 Honda TRX420FA6 Rancher 4x4 AT DCT EPS [IRS]
2023 Honda TRX420FE1 Rancher 4x4 ES [SRA]
2023 Honda TRX420FM1 Rancher 4x4 [SRA]
2023 Honda TRX420FM2 Rancher 4x4 EPS [SRA]
2023 Honda TRX420TE1 Rancher 2x4 ES [SRA]
2023 Honda TRX420TM1 Rancher [SRA]
2024 Honda TRX420FA2 Rancher 4x4 AT DCT EPS [SRA]
2024 Honda TRX420FA5 Rancher 4x4 AT DCT [IRS]
2024 Honda TRX420FA6 Rancher 4x4 AT DCT EPS [IRS]
2024 Honda TRX420FE1 Rancher 4x4 ES [SRA]
2024 Honda TRX420FM1 Rancher 4x4 [SRA]
2024 Honda TRX420FM2 Rancher 4x4 EPS [SRA]
2024 Honda TRX420TE1 Rancher 2x4 ES [SRA]
2024 Honda TRX420TM1 Rancher [SRA]