Hastings 3.875" Bore Standard Piston Ring Set (2M4985)
- Includes top compression rings, second compression rings, and oil control rings
- Helps in the the heat transfer process between the piston and cylinder wall
- Controls combustion chamber gases allowing the piston to transfer the energy of the expanding combustion gases, to the crankshaft
- Promotes side sealing that prevents oil from being forced under and behind the ring resulting in better oil economy
- Reverse twist ring along with a taper-machined ring face duplicates the OD bottom side scraping edge of a positive twist torsional ring
- Three-piece design allows rails to be manufactured with a small cross sectional area for better conformability to bore
- Provides uniform pressure through four steel rails and two expanders assuring positive oil control
- Made in the USA
- Due to the thermal conductivity and design of KB pistons, special attention is required to the top ring end gap. Please read instructions furnished with piston for correct ring installation.
- Includes enough rings for two pistons (unless noted).
- Two rings per groove, except for the rails that will be two rail rings per one expander ring.
Top Compression Rings are Barrel Face
Second Compression Ring are Reverse Torsional Taper Face
Oil Control Rings are Three Piece Flex Vent
| Compatible Vehicles | |||
| Years | Make | Make | Notes |
| 1999-2000 | Harley-Davidson | Dyna Convertible FXDS-Conv | |
| 2004-2005 | Harley-Davidson | Dyna Low Rider EFI FXDLI | |
| 1999-2005 | Harley-Davidson | Dyna Low Rider FXDL | |
| 2005 | Harley-Davidson | Dyna Super Glide Custom EFI FXDCI | |
| 2005 | Harley-Davidson | Dyna Super Glide Custom FXDC | |
| 2004-2005 | Harley-Davidson | Dyna Super Glide EFI FXDI | |
| 1999-2005 | Harley-Davidson | Dyna Super Glide FXD | |
| 2004-2005 | Harley-Davidson | Dyna Super Glide Sport EFI FXDXI | |
| 1999-2005 | Harley-Davidson | Dyna Super Glide Sport FXDX | |
| 2001-2003 | Harley-Davidson | Dyna Super Glide T-Sport FXDX-T | |
| 2004-2005 | Harley-Davidson | Dyna Wide Glide EFI FXDWGI | |
| 1999-2005 | Harley-Davidson | Dyna Wide Glide FXDWG | |
| 2001 | Harley-Davidson | Dyna Wide Glide Screamin Eagle FXDWG2 | |
| 2002 | Harley-Davidson | Dyna Wide Glide Screamin Eagle FXDWG3 | |
| 1999-2006 | Harley-Davidson | Electra Glide Classic EFI FLHTCI | |
| 1999-2005 | Harley-Davidson | Electra Glide Classic FLHTC | |
| 2003-2006 | Harley-Davidson | Electra Glide EFI FLHTI | |
| 1999-2006 | Harley-Davidson | Electra Glide FLHT | |
| 1999-2006 | Harley-Davidson | Electra Glide Ultra Classic EFI FLHTCUI | |
| 2006 | Harley-Davidson | Electra Glide Ultra Classic Screamin Eagle FLHTCUS | |
| 1999-2006 | Harley-Davidson | Road Glide EFI FLTRI | |
| 1999-2002 | Harley-Davidson | Road Glide FLTR | |
| 1999-2006 | Harley-Davidson | Road King Classic EFI FLHRCI | |
| 2004-2006 | Harley-Davidson | Road King Custom EFI FLHRSI | |
| 2004-2006 | Harley-Davidson | Road King Custom FLHRS | |
| 2000-2006 | Harley-Davidson | Road King EFI FLHRI | |
| 1999-2006 | Harley-Davidson | Road King FLHR | |