Kb Pistons Super Duty Piston - 4.250" Bore M8 107 TO 124" STD 11.8:1 — Harley-Davidson (2017-2025)
KB Pistons Super Duty piston for Milwaukee-Eight (M8) engines, sold as a pair with all rings, wrist pins, and locks included. Built for 4.250" bore with 11.8:1 compression ratio and flat-top design to accommodate 1mm oversize valves.
Features
- Anodized top ring groove and crown
- Line2Line Abradable skirt coating (.003" thickness) for zero initial fit and quiet operation
- Round wire locks
- Premium Hastings 1.2mm top ring with Steel Nitride coating and Ductile Napier second ring
- Forced wrist pin oiling
- Flat-top design with 1.2cc dish and 1.083" compression height
- All rings, wrist pins, and locks included
- Sold as a pair
Specifications
- Brand: KB Pistons
- Manufacturer Part #: KB595LCA.STD
- UPC: 800745276155
- Engine: Milwaukee-Eight (M8)
- Bore: 4.250"
- Compression Ratio: 11.8:1
- Compression Height: 1.083"
- Piston Dish: 1.2cc flat-top
- Weight: 2.5 lbs per pair
- Country of Origin: Mexico
Fitment
Fits Harley-Davidson Milwaukee-Eight (M8) engines with 4.250" bore.
Frequently Asked Questions
What's included in this piston kit?
A pair of pistons, premium Hastings rings, stainless steel wrist pins, and round wire locks — everything needed for a complete piston swap.
Will these pistons work with 1mm oversize valves?
Yes — the flat-top design and valve pockets are sized specifically to accommodate 1mm oversize valves without interference.
What does Line2Line Abradable skirt coating do?
The .003" coating allows the piston to start with zero initial clearance, then hones in as you ride for a tight, quiet-running fit without excessive bearing wear.
Do I need to hone my cylinders before installing these?
Your engine builder can assess your cylinder condition. The Abradable coating is designed to work with proper honing practices.
What compression ratio do these give?
These are 11.8:1 pistons for your bore size — verify with your engine builder that this matches your build target and fuel requirements.
| BRAND | Kb Pistons |
| TYPE | Piston kits & Components |
| SKU | 824-01832 |
| WEIGHT | 2.5 lb |
