K&N Motorcycle Oil Filter KN-173C — High-Flow Replacement with Welded Wrench-Off Nut

The K&N KN-173C motorcycle oil filter is a high-flow, long-life replacement filter with an integrated welded wrench-off nut for faster oil changes on compatible Harley-Davidson Dyna and FXB models.

This K&N Performance Oil Filter is built to meet the demands of powersports riding by combining heavy-duty construction with premium synthetic filtration media. It’s engineered to maintain strong oil flow while trapping contaminants, and is tested for capacity and structural integrity. The KN-173C is designed as a direct, application-specific replacement for many Harley-Davidson Dyna and select FXB Sturgis models from the 1980s and 1990s, and it accepts conventional, synthetic, or blended oils.

How does the KN-173C improve engine protection?

The KN-173C uses high-efficiency synthetic filter media with consistent pleating to capture wear particles and contaminants without restricting oil passage. Its construction raises the filter’s dirt-holding capacity and resists collapsing under pressure, helping the oil system stay cleaner between changes.

• Premium synthetic media for finer particle capture
• Uniform pleats for steady oil flow
• Laboratory-tested burst strength and capacity

Will this filter fit my Harley-Davidson Dyna or FXB?

KN-173C is made as an application-specific replacement for several Harley-Davidson models from the 1980s and 1990s. Check the compatibility list or your vehicle’s parts reference to confirm fitment before purchasing to ensure correct installation and sealing.

• Compatible with multiple Dyna models from 1991–1998
• Includes older FXB Sturgis models (1980–1982)
• Designed to match OEM dimensions and mounting points

How does the welded wrench-off nut help during oil changes?

The integrated welded nut on the KN-173C lets you remove the filter with common sockets or a wrench instead of relying solely on a strap-style tool or hand grip. That feature reduces the chance of spills and speeds service, especially in tight spaces on motorcycles.

• Welded nut fits standard sockets for quick removal
• Reduces the need for specialized filter wrenches
• Simplifies changes in cramped engine bays

Can I use high-end synthetic oils with this filter?

Yes—the KN-173C is optimized with a part-specific bypass/pressure relief valve and media compatible with premium synthetic oils. It supports a broad range of oil types, so you can choose synthetic, conventional, or blended lubricants according to your maintenance plan.

• Valve tuned for the filter’s part number and flow characteristics
• Safe with synthetic, conventional, and blended oils
• Engineered to preserve oil flow under varied conditions

Who is this for? The K&N KN-173C is aimed at riders who own compatible Harley-Davidson Dyna or FXB models and want a robust, service-friendly oil filter. It’s a good choice for enthusiasts who perform their own maintenance, shop technicians seeking a direct replacement, and riders who prefer long-duration service intervals when using recommended oils.