How to Clean Sportster Cylinder Fins

Harley-Davidson Sportster cylinders come with a brushed-aluminum finish, a chrome finish or are painted with black wrinkle paint. The cooling fins on the cylinders are notorious for trapping and retaining road grime and dust, and the texture of the wrinkle paint exacerbates the problem with its many ridges and valleys. Proper cleaning of the cylinder fins is essential to maintain their ability to radiate heat into the atmosphere and prevent engine damage due to overheating. Remove road grime, salt, and other accumulations from the fins as a part of regular service on your Sportster engine.

Things You'll Need

• Garden hose
• Soap
• Bucket
• Toothbrush or paintbrush
• Air compressor
• Rubber tip blowgun
• Microfiber cloth

Instructions

1. Wet the cylinder fins down with a low-pressure hose. Do not use high pressure or a spray nozzle to wet the Sportster engine.

2. Mix a solution of water and soap. Use a mild soap such as dishwashing detergent that has oil-cutting properties without the use of strong solvents that may damage the finish or rubber components on the engine.

3. Apply soap solution to the cylinders. Scrub the areas between the cylinder fins with a toothbrush or clean paintbrush to remove the accumulated grime. Avoid getting the air cleaner wet. Rinse the cylinders with clean water. Repeat until the cylinders are clean.

4. Blow the cylinders dry with low-pressure compressed air using a blowgun with a rubber tip. Do not blow on any rubber engine components, or electrical connectors or components.

5. Wipe the rest of the engine dry with a lint-free, microfiber cloth.

Tips & Warnings

• Use magnesium and aluminum polish, or chrome polish, if you wish to further restore the Sportster cylinder fins to factory condition. Your authorized Harley-Davidson dealer will recommend polish brands and techniques for your specific application.

• A leaf-blower may be used in lieu of the compressor and blowgun. Ensure the area around the bike is clean and free of dirt that may become airborne during the drying process.

• Do not attempt to wash a hot engine. Allow the Sportster engine to cool approximately six hours before washing.

• Do not use a pressure washer or car-wash wand to clean the engine. High pressure water can damage the finish and force water into the weatherproof electrical connectors.

• Do not use a wire brush to clean the cylinder fins, or you will damage the finish.