Keith Black Pistons Flat Top Pistons KB258.030 for Big Twin 1984-1999
$566.15
Skip to product information
Keith Black Pistons Flat Top Pistons KB258.030 for Big Twin 1984-1999
$566.15
Upgrade your motorcycle engine with Keith Black Pistons flat top pistons, engineered from a high-performance hypereutectic alloy featuring a 16% silicon content. This durable cast material provides a low thermal expansion rate that allows for tighter piston-to-cylinder clearances, making it an ideal choice for demanding air-cooled engines.
Designed to fit Big Twin 1984-1999 models equipped with an Evolution engine, this complete replacement kit achieves an 8.6:1 compression ratio with 80cc head chambers. It replaces OEM part number 21944-83 and includes two pistons, rings, wrist pins, and retaining clips for a full overhaul.
Key Features
| Brand | Keith Black Pistons |
| Manufacturer Part Number | KB258.030 |
| OEM Replacement Number | 21944-83 |
| Bore Size | 89.6 mm |
| Stroke | 108 mm |
| Material | Hypereutectic Alloy (16% Silicon) |
| Piston Style | Flat Top |
| Compression Ratio | 8.6:1 with 80cc Head Chamber |
| Oversize | +0.76 mm |
| Product Weight | 1.8 kg |
Highlights
- Cast from 16% silicon hypereutectic alloy for high thermal stability
- Low thermal expansion enables tighter piston-to-cylinder clearance
- Delivers an 8.6:1 compression ratio with standard 80cc combustion chambers
- Direct replacement for OEM part #21944-83
Compatibility
Compatible with Harley-Davidson Big Twin models from 1984 to 1999 equipped with Evolution (Evo) engines.
What's included
- 2 x Hypereutectic Flat Top Pistons
- 1 x Full Set of Piston Rings
- 2 x Wrist Pins
- 4 x Retaining Clips
Downloads
Frequently asked questions
|