KPMI White Diamond Exhaust Valve - M8 1.284 OS — Harley-Davidson Softail Deluxe, Softail Fat Boy, Softail Fat Boy 114 (2018-2020)

KPMI White Diamond exhaust valve for Harley Milwaukee-Eight (M8) engines, sized 1.284 inches oversize for high-performance and engine rebuild applications. The White Diamond coating enhances durability and heat resistance in demanding conditions.

Features

• 1.284 inch oversize diameter
• White Diamond hard coating
• Direct M8 replacement valve
• Heat-resistant design for high-performance builds

Specifications

• Brand: KPMI
• Manufacturer Part #: 20-21017H
• Size: 1.284 inch oversize
• Length: 3.5 in
• Weight: 0.2 lbs

Fitment

Fits Harley-Davidson Milwaukee-Eight (M8) engines. This oversize valve is for rebuilt or high-performance engine builds and is not a direct replacement for unmodified stock M8 heads.

Frequently Asked Questions

Will this fit a stock Milwaukee-Eight engine?

No — this 1.284 OS valve is for rebuilt or ported M8 heads. Stock engines use standard-size exhaust valves.

What is White Diamond coating?

A hard ceramic coating that resists heat and wear, improving durability in high-performance applications.

Do I need new valve seats installed for this oversize valve?

Yes — oversize valves require matching oversize valve seats cut into the cylinder head by a machine shop.

Can I use this with my stock intake valve?

You should consult your engine builder — mixing stock and oversize components requires proper flow matching for reliable performance.