K&N Engine Air Filter – High-Flow Premium Powersport Filter for Suzuki DRZ400S/SM/E and KLX400R/SR (2000-2019) SU-4000

Overview

The K&N Engine Air Filter SU-4000 is engineered for riders who want an easy upgrade that enhances the way their bike breathes. Specifically designed to fit the factory air box, this high-flow filter is built for 2000–2019 Suzuki DRZ400S/SM/E and 2003 Kawasaki KLX400R/SR models, making installation straightforward and rewarding. It’s a washable, reusable alternative to disposable filters, and it comes backed by K&N’s renowned warranty that travels with the vehicle.

What makes this filter stand out

With state-of-the-art filter media, the design aims to maintain a robust air path while filtering dust and debris. Riders may notice more responsive throttle feel and steadier power delivery as the engine breathes easier under load—from optimistic highway accelerations to technical trail climbs. This isn’t a promise of dramatic changes, but a potential improvement you can experience with regular maintenance.

• ULTIMATE LONGEVITY: 10-Year/Million Mile Limited Warranty protects for the life of your vehicle
• ENGINEERED POWER: State-of-the-art air filter media is designed to increase horsepower and acceleration as well as improve overall engine performance
• EASY INSTALLATION: Pre-oiled and ready to install. One of the easiest and most cost-effective upgrades for your motorcycle or ATV for quick performance gains
• SAVES MONEY: K&N high-flow replacement air filters will save you $250 over 10 years by avoiding disposable filters
• ECO-FRIENDLY: Using a washable, reusable product helps reduce replacement waste. A K&N filter will last longer than 10 disposable filters

Fit, installation, and real-world use

Designed for a snug, factory-fit experience, the SU-4000 drops into your stock air box with minimal tools and fuss. It arrives pre-oiled, enabling a quick, clean swap that’s ideal for weekend wrenchers and seasoned riders alike. Whether you ride through dusty backroads, ride-ready urban commutes, or weekend trails, the filter is built to stand up to heat, dust, and regular maintenance cycles, keeping intake airflow consistent when you need it most.

Why choose K&N for your powersport machine

• Long-lasting filtration you can clean and reuse, reducing waste and replacement costs
• Proven performance tested on tough tracks, with a focus on real-world riding scenarios
• A budget-friendly upgrade that complements stock components and factory boxes

Environment and durability

Beyond performance, the filter emphasizes sustainability through a washable design and a warranty that accompanies the vehicle. With thoughtful material choices and a straightforward maintenance routine, it’s a practical upgrade for riders who value reliability and efficiency on the road or trail.