KPMI Valve Seat - Powd Metal 54.1mm EVO BIG Twin 1984-1999/XL — Harley-Davidson (1980-2017)

KPMI Kibblewhite valve seat in powdered metal for Harley EVO Big Twin and Sportster, 1984–1999. Kibblewhite's proprietary material resists microwelding and seat recession while running on leaded, unleaded, methanol, and ethanol blends with excellent thermal stability.

Features

• Kibblewhite proprietary powdered metal compound
• Compatible with leaded, unleaded, methanol, and ethanol fuels
• Resists microwelding and valve face recession
• Generous radius on leading edge for easier installation
• Thermal stability for street and performance riding

Specifications

• Brand: KPMI
• Manufacturer Part #: 10-SC541
• Diameter: 54.1 mm
• Length: 3.6 in
• Width: 2.3 in
• Height: 0.85 in
• Weight: 0.15 lbs

Fitment

Fits Harley-Davidson EVO Big Twin and Sportster (XL) models, 1984–1999.

Frequently Asked Questions

Will this valve seat work with ethanol fuel?

Yes — Kibblewhite's proprietary material is fully compatible with ethanol and methanol fuel blends, as well as leaded and unleaded gasoline.

Does this fit my 2000+ Sportster?

No — this part is for 1984–1999 EVO engines. 2000 and newer Sportsters use different seat specifications.

What's the main advantage over OEM seats?

Kibblewhite's material resists microwelding and recession that can occur with stock seats, extending valve life and improving reliability.

Is installation difficult?

The generous radius on the leading edge makes seating easier during installation, but valve seat work requires proper machine shop equipment and expertise.

Can I use this with a performance cam?

Yes — this seat is suitable for street and performance applications, including higher-lift cams and increased valve speeds.