Kb Pistons Hypereutectic Cast Piston - Pistons EVO 80ci 10.5:1 .010 — Harley-Davidson (1984-1999)

KB Pistons Hypereutectic Cast Piston for EVO 80ci engines with 10.5:1 compression ratio and .010 oversized bore. Cast from 16% silicon hypereutectic alloy for low thermal expansion, tight piston-to-wall clearance, and reduced wear in air-cooled Harley engines running on pump fuel.

Features

• 16% silicon hypereutectic alloy
• Low thermal expansion rate
• Tight piston-to-cylinder-wall clearance
• Optimal ring seal and reduced wear
• Suitable for stock to mild compression ratios up to 10.5:1

Specifications

• Brand: KB Pistons
• Manufacturer Part #: KB266.010
• UPC: 800745061409
• Compression Ratio: 10.5:1
• Bore Size: .010 oversized
• Engine: EVO 80ci
• Weight: 2.7 lbs
• Country of Origin: Mexico

Fitment

Fits air-cooled EVO 80 cubic inch engines. Designed for stock to mild compression applications running on pump fuel.

Frequently Asked Questions

What compression ratio are these pistons rated for?

10.5:1 compression ratio — best suited for stock or mild builds running standard pump fuel.

Will these work in a high-compression or boosted engine?

No — hypereutectic pistons are designed for stock to mild compression up to 10.5:1. High-compression or forced-induction builds require forged pistons.

Why hypereutectic instead of forged?

Hypereutectic alloy offers low thermal expansion, tight ring seal, quieter operation, and reduced wear in air-cooled engines. Forged pistons are needed only for aggressive compression or boost.

Is this a complete piston kit or just the piston?

This is the individual piston (.010 oversized). Check with your engine builder to confirm you need all matching components — rings, pins, and clips may be ordered separately.