How to Wash a Dirt Bike and Inspect It

Step By Step

1. Let it cool, plug the exhaust

   Wash a cold bike. Honda and Yamaha both say to let the engine, pipe and brakes cool first. Then plug the silencer outlet so no water gets in. Honda says water in the muffler can stop the bike starting and rusts it from the inside.

   • Exhaust plug
   • Rag and plastic bag

2. Cover the intake

   Water in the air filter can keep the engine from starting. Fit an airbox wash cover or block the air duct, and keep the seat on. Yamaha says never to spray with the seat or side covers off. Push the plug cap and every connector home before you start.

   • Airbox wash cover

3. Rinse first, then wash

   Knock the loose dirt off with a gentle spray first. Then put cleaner on the wet bike and work it with a soft brush or sponge. KTM says never to put cleaner on a dry bike. Yamaha says to keep degreaser off seals, sprockets, the chain and the axles.

   • Garden hose
   • Motorcycle cleaner
   • Soft brush

4. Keep the jet off seals

   A seal lip holds back splash and mud, not a pressure washer. KTM says high pressure forces water into bearings, connectors and throttle cables. Inside, water thins the grease and the races rust. Honda says not to use a pressure washer at all.

   Pressure washer distance

   Bike	Spec	Source
   KTM / Husqvarna / GASGAS	60 cm (23.6 in) minimum	KTM 250 SX-F 2024 owner’s manual, p. 138
   Honda CRF250R / CRF450R	No pressure washer	Honda CRF250R 2025 owner’s manual, p. 59-60 (low-pressure garden hose)
   Yamaha YZ250F / YZ450F	No jet at seals or bearings	Yamaha YZ250F 2026 owner’s service manual, p. 1-34

   If your manual gives no distance, skip the pressure washer. Use a garden hose and keep any jet well away from bearings, seals and electrics.

   Careful. Close up, the jet lifts the seal lip and pushes water straight into the bearing. Stay back and never aim at a seal.

5. Know the no-spray zones

   Every pivot rides on bearings: the steering head, both wheel hubs, the swingarm pivot and the linkage. Honda also lists the master cylinders, the chain, the stop button, the throttle body and the electrics under the tank and seat. Yamaha adds fork seals, hoses and the muffler.

6. Dry it and dry the brakes

   Dry the bike with a chamois or soft cloth, then pull the exhaust plug and wash cover. Ride slowly and use both brakes a few times to dry the pads and discs. KTM adds a short ride until the engine is warm, and pushing back the rubber caps on the bar controls so trapped water can dry.

   Careful. Wet brakes grab late and feel weak. Test them at low speed before you ride hard.

7. Lube the chain and pivots

   Lube the chain as soon as it is dry so it can’t rust. Spray the inside of the bottom run and wipe off the extra. Once the bike is cool, KTM says to lube all moving parts and pivot points, like lever pivots and cable ends.

   Careful. Keep lube, wax and polish off the brake discs, pads and tires.

   Shop tip. KTM sprays bare metal with a corrosion inhibitor after a wash. Skip the brake discs and the exhaust.

8. Look for cracks

   Clean metal shows cracks that mud hides. Use a light and go over the welds on the frame, the subframe and the swingarm, especially around the steering head, engine mounts and footpegs. Look for hairline cracks and dull lines in the paint.

   Careful. A cracked or bent frame or swingarm gets replaced. KTM does not permit repairs to either.

9. Look for leaks

   Honda says a clean bike makes leaks easy to spot. Wipe the fork tubes and look for an oil ring under the seal. Then check the shock body, the engine cases and gaskets, coolant hoses and radiators, and the brake hoses and calipers for anything wet.

   Shop tip. Ride, then look again. A clean bike that comes back wet in one spot points right at the leak. Follow the wet trail up to its highest point.

10. Check bolts, cables and hoses

    Go over the bolts that shake loose: axle nuts, bar clamps, triple clamp pinch bolts, engine mounts, chain adjuster lock nuts and the silencer mounts. Check cables and hoses for kinks, rubbing and cracks, and that the throttle snaps shut. Look at the chain slider and rollers for wear.

    Careful. Axle, brake and steering fasteners are safety parts. Tighten them to the torque in your manual, never by feel.