The Complete Guide to S&S Air Filter Cleaning: Maximize Performance and Protect Your Engine
Proper and regular S&S air filter cleaning is a non-negotiable maintenance task for any Harley-Davidson or performance V-twin owner. Neglecting this simple service can lead to lost power, poor fuel economy, and accelerated engine wear. This definitive guide will walk you through every step of correctly cleaning and re-oiling your S&S air filter, explain why it's critical, and help you avoid common mistakes that can damage your engine. By following these proven procedures, you will ensure your motorcycle breathes easily, runs strong, and lasts for miles to come.
Understanding Your S&S Air Filter and Why Cleaning Matters
The S&S air filter is a crucial component of your motorcycle's intake system. Unlike disposable paper filters, S&S high-performance filters are typically made of layered, oiled cotton gauze or specialized foam over a metal mesh support. The oil traps dust, dirt, and debris, preventing them from entering your engine's cylinders. Over time, this layer of grime builds up, restricting the airflow. A clogged filter chokes the engine, forcing it to work harder to pull in air. This results in a rich air/fuel mixture (too much fuel, not enough air), which causes symptoms like sluggish throttle response, reduced horsepower, and black smoke from the exhaust. More critically, if the filter is damaged or improperly maintained, abrasive particles can slip through, acting like sandpaper on piston rings, cylinder walls, and bearings. Regular cleaning removes this restrictive grime and restores the filter's ability to trap contaminants effectively. For most riders, cleaning is necessary every 5,000 to 10,000 miles, but if you frequently ride in dusty, wet, or dirty conditions, you should inspect and likely clean the filter every 2,000 to 3,000 miles.
Gathering the Correct Tools and Cleaning Supplies
Before you begin, assemble the right materials. Using incorrect chemicals or tools can ruin your filter. You will need a clean workspace, a sink or large bucket, and gloves. The essential supplies are an S&S brand cleaner or a dedicated air filter cleaning solution, and the correct S&S filter oil. Do not substitute these with generic products. S&S cleaner is formulated to break down the specific oil and grime on their filters without damaging the cotton gauze or glue bonds. Using harsh solvents like gasoline, kerosene, or carburetor cleaner can break down the filter's internal seals and deteriorate the filtering material. You will also need S&S filter oil, which is tacky and designed to stay in place while trapping particles. Other oils, like motor oil, are too thin and will be sucked into the engine, potentially causing damage. Finally, have clean, lint-free towels and a plastic bag for the oiling process ready.
Step-by-Step Removal of the S&S Air Filter
Always start with a cool engine. Locate the air filter assembly on your motorcycle; it is usually a round or oval cover on the side of the engine. Using the correct size socket or screwdriver, loosen the fastener or screw at the center of the filter cover. Some models may have multiple screws around the perimeter. Carefully remove the fastener and the outer cover. You will now see the air filter element. Note its orientation before removal. Gently pull the filter straight off the intake mount. Be cautious not to drop any debris into the now-exposed air intake hole. Immediately place a clean cloth or tape over the intake opening to prevent any tools, dirt, or cleaning fluid from accidentally falling into the engine.
The Deep Cleaning Process: Removing All Grime and Old Oil
This step thoroughly removes all old oil and embedded dirt. First, tap the filter gently on a hard surface to dislodge loose, dry dirt. Submerge the filter completely in a container filled with S&S Air Filter Cleaner or your chosen approved solution. Agitate it gently, squeezing the filter repeatedly to work the cleaner through all the pleats and layers. Do not twist or wring the filter, as this can damage the internal structure. Let it soak for 10-15 minutes as directed on the cleaner's label. After soaking, agitate and squeeze it again. You will see the solution turn dark as dirt and oil are released. Dump out the dirty cleaner. Next, rinse the filter thoroughly under a gentle stream of lukewarm water from the inside out. This means holding the filter with the interior metal mesh facing you and spraying water through the filter material from the inside. This pushes contaminants out of the filter, the opposite direction they entered. Continue rinsing until the water runs completely clear. This is vital; any residual cleaner left in the filter will break down the new oil you apply later.
Drying: The Most Important Step You Cannot Rush
Improper drying is a leading cause of engine damage. The filter must be 100% completely dry before applying new oil. Any water or moisture trapped inside will mix with the oil, creating a paste that blocks airflow and is ineffective at trapping dirt. Shake off excess water vigorously. Then, set the filter on a clean towel in a warm, dry, dust-free area with good air circulation. Allow it to air dry naturally. This process can take several hours, and for dense filters, it may take up to 24 hours. Do not use compressed air to dry it, as the high pressure can separate the gauze layers or create holes. Never apply heat from a hair dryer, oven, or space heater, as this can melt glue seams or warp the filter. Patience here is non-negotiable for proper filter function.
Applying the Filter Oil Correctly and Evenly
Once the filter is totally dry, you are ready to re-oil. Pour a generous amount of S&S Filter Oil into a clean plastic bag. Place the dry filter into the bag. Seal the bag and, from the outside, knead and massage the oil into the filter. Ensure you work the oil evenly throughout every part of the filter material. The goal is a uniform, tacky coating on every strand of the filter medium. It should look evenly saturated, not dripping wet, and not have any dry spots. After massaging, remove the filter from the bag and squeeze out any excess oil. You should see a consistent color throughout with no dry, light-colored patches. Wipe any oil from the center mounting hole and the outer sealing surfaces.
Reinstalling the Clean Air Filter and Final Checks
Remove the cover from the air intake hole. Take your freshly oiled filter and align it properly on the intake mount. Push it firmly and evenly into place, ensuring the sealing gasket is seated correctly all around. Replace the filter cover and tighten the center fastener or perimeter screws snugly. Do not overtighten, as this can crack the cover or strip the threads. Perform a visual check to make sure the filter is seated flush with no gaps. Start the engine and listen for any unusual sounds or air leaks. Let the engine idle for a minute, then take a short, gentle ride. The motorcycle should idle smoothly and feel more responsive. You have now successfully completed an S&S air filter cleaning, a fundamental service that protects your investment and maintains peak performance.
Common Mistakes and Misconceptions to Avoid
Many well-intentioned riders make errors that compromise their filter. One major mistake is using too much oil. A dripping filter can allow excess oil to coat Mass Air Flow sensors (if equipped) or be drawn into the engine, potentially fouling spark plugs. Another error is using the wrong oil, as previously stated. Some riders clean their filter too aggressively with brushes or high-pressure water, which damages the delicate filtering material. Perhaps the most dangerous mistake is rushing the drying process. Installing a damp filter is worse than not cleaning it at all. Finally, do not clean the filter too frequently; unnecessary cleaning wears out the material. Follow the inspection guidelines—if it looks dirty, clean it. If not, leave it be.
Long-Term Care and When to Replace Your S&S Filter
With proper care, an S&S air filter can last for many years. However, it is not immortal. Each cleaning cycle puts some wear on the cotton gauze. During every cleaning, inspect the filter meticulously. Hold a bright light behind it and look for any thin spots, holes, or tears in the material. Check the rubber sealing gasket for cracks, dryness, or brittleness. Examine the metal end caps and mesh for rust or separation from the filtering material. If you find any damage, no matter how small, you must replace the filter immediately. A compromised filter is no longer filtering. S&S filters are designed for long service life, but they are a maintenance item, not a lifetime component. Replacing a worn filter is far less expensive than rebuilding an engine damaged by dirt ingestion.
Troubleshooting Performance Issues Related to the Air Filter
If you experience performance problems after cleaning, retrace your steps. A rough idle or loss of power can indicate an air leak caused by a filter that is not sealed properly on the intake mount. Check the installation. If the engine runs poorly and black smoke is present, the filter may be over-oiled or still saturated with cleaning solvent, restricting airflow. Remove and inspect it. If performance improved initially but then degraded very quickly, you may have installed a filter that was not completely dry, causing dirt to clump and block airflow rapidly. In all cases, the solution is to remove the filter, verify it is undamaged, ensure it is completely dry, and re-oil it carefully following the exact steps outlined. This systematic approach to S&S air filter cleaning is the cornerstone of reliable motorcycle performance and longevity.