K&N High Flow Air Filter for Yamaha WR400F Dirt Bike
K&N High Flow Air Filter for Yamaha WR400F Dirt Bike
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Description
K&N Powersports High-Flow Air Filter
Upgrade your machine’s performance with a K&N High-Flow Powersports Air Filter. Designed to increase airflow while providing superior filtration, these premium reusable filters help your engine breathe better for improved horsepower, throttle response, and overall performance.
Built with oiled cotton gauze media, K&N filters capture dirt and debris while allowing more air to reach the engine compared to traditional paper filters. The result is better performance and long-term reliability for motorcycles, ATVs, UTVs, and other powersports machines.
Unlike disposable filters, K&N air filters are washable and reusable, helping reduce maintenance costs over time. With proper cleaning and oiling, one filter can last for the life of your vehicle.
Key Features
High-flow design improves airflow and engine performance
Superior filtration protects your engine from dirt and debris
Washable and reusable for long-term value
Durable oiled cotton gauze construction
Direct OEM replacement for easy installation
Designed specifically for motorcycles, ATVs, UTVs, and other powersports applications
Why Choose K&N?
K&N is a global leader in high-performance filtration, trusted by riders and racers worldwide. Their powersports air filters are engineered to deliver maximum airflow without sacrificing engine protection, helping you get the most out of your ride.
Technical Specifications
- MFG. Part Number DU-9001
Vehicle Information
Yamaha WR400F Dirt Bike (1998-2000)
The Yamaha WR400F, produced from 1998 to 2000, was a pioneering four-stroke enduro motorcycle renowned for its powerful engine and exceptional off-road capabilities. This model featured a single-cylinder, four-stroke, DOHC, 5-valve engine with a 399 cc displacement across all years. It was offered as a single "Enduro" or "Off-road" model, without distinct sub-trims. The WR400F saw significant evolution during its initial run. Introduced in 1998, it was derived from the YZ400F motocrosser. In 1999, it received updates to its suspension and engine calibration, alongside carburetor modifications for improved starting. The 2000 model year brought substantial changes, including a slimmer seat and fuel tank (reducing capacity to 8 liters), making the bike 2.5 kg lighter. Other enhancements included faster suspension damping, a stiffer lower triple-clamp, and a repositioned steering head to shorten the wheelbase, alongside further chassis, ignition, and engine refinements. FAQ:
Q: How do I ensure this product fits my Yamaha WR400F?
A: To guarantee compatibility, please use the year and edition selector at the top of this page to specify your exact model year.
Maintenance
| Component | Interval | Details |
| Engine Oil Changes | 1998: 5 h (aggressive riding) or 10 h (recreational); 1999-2000: 10 h (aggressive riding) or 15 h (recreational) | |
| Oil Filter | Every oil change (2000 model); or every 6,000 km (general Yamaha recommendation) | |
| Air Filter Service | 5 h (aggressive riding) or 10 h (recreational) | Regular inspection, cleaning, and re-oiling are crucial, especially after riding in dusty conditions. |
| Spark Plug | Inspection at 100 h or 1 year | |
| Coolant | Leakage inspection at 20 h (or 3 months) and 100 h (or 1 year) | No specific replacement interval provided. |
| Valve Inspections | 1998: 10 h (aggressive riding) or 20 h (recreational); 1999: 20 h (all styles); 2000: 20 h (aggressive riding) or 30 h (recreational) |