Complete Guide: How to Correctly Clean a Motorcycle Engine

Like any other motor vehicle engine, a motorcycle’s engine is susceptible to dirt and will get greasy and grimy with time. The engine being the heart of your motorcycle should be cleaned regularly for maximum performance with excellent fuel efficiency. If left uncleaned, the engine will accumulate too much grease and grime leading to overheating and consequently reduced performance, let alone the fuel consumption. While detailing and cleaning your bike’s engine can get difficult, you can surely enjoy the cleaning process-just listen to your favorite music while cleaning. Additionally, cleaning and detailing your motorcycle engine by yourself is not only fulfilling but also saves you a substantial amount of money that you could have used in a professional detail shop. There are several steps you should follow to correctly clean a motorcycle engine. This guide will see you through. 

What do I Need to Clean My Motorcycle Engine?  

There are numerous products you can use to get your engine sparkling and up to the task. Below are the main supplies you will need: 

  • Small brush with soft bristles   
  • Paraffin      
  • Automotive blow dryer
  • Air nozzle 
  • Warm water with detergent 
  • Citrus-based degreaser (orange or lemon) 
  • Plastic bags 
  • Air Nozzle 
  • Chrome polish 
  • Masking tape 
  • Water hose and spray nozzle-preferably the high-pressure type 
  • Rubber seal protectant 
  • Dry towels 
  • Air compressor and air hose/ automotive blow dry 

Getting Started 

To kick-off the cleaning process, ensure you start the engine for a few minutes to allow the engine components to warm. Make sure it doesn’t get too hot. Once warm, create way to the interior of the engine by removing the covers, faring components, panels and even the gas tank. If you’re not conversant with the arrangement of this components, you can ask your friend to give you a hand. Nonetheless, removing these components is not hard or complicated-you’ll get along pretty fast. Next, ensure you cover the sensitive parts such as the fuse block, ignition coil, carburetor, spark plug and other electronic components using plastic bags or masking tapes. You are now ready to clean different parts of the engine as outlined below: 

Cleaning the Engine Aluminum Fins

The motorcycle engine aluminum fins are attached to the cylinder head of the engine to act as radiator to cool the engine by drawing heat from the combustion chamber and dissipating it in the surrounding air. With time, the fins accumulate dust, dirt, grease and grime reducing its cooling efficiency.  To clean the fins, proceed as follows: 

Step 1 

Place warm water to a small, clean bucket and add a household detergent. You can use the S100 Total Cycle Cleaner Aerosol or Gel or any other brand of your choice.   

Step 2

Using the high-pressure water hose, spray the engine’s cooling fins with water at low pressure to dislodge loose dirt and debris. Try to avoid the motorcycle’s air box or air cleaner. 

Step 3 

Using the small brush with soft bristles, scrub the cylinder head and in between the cooling fins using soapy water. Alternatively, you can use sandpaper to scrub in between the fins and around the corners.  For the edges of the fins, you can use Dremel sanding to get a nice mirror looking finish of the fins.   Rinse the cylinder and fins often to wash away the loosened buildup. 

Step 4 

Rinse and cylinder and in between the cooling fins thoroughly with clean water preferably at high pressure. Next, blow dry the cylinder up to and exhaust system, using an automotive blow dryer set to Low. Finally, wipe any remaining water droplets using a lint-free dry towel and leave it to dry.  

Cleaning the Engine Case and Cylinder 

Clean motorcycle engine case and cylinder is very simple. You simply use a brush with a degreaser/cleaner to break up the grease and grim then rinse thoroughly.  Use the below steps to clean the engine case and cylinder. 

Step 1- Spray on Degreasing Agent and Let it Soak for Some Time

After ensuring that sensitive parts are covered with plastic bags as earlier stated, spray a citrus based degreasing agent on the surface of the engine case and cylinder. Follow the manufacturer’s instructions and ensure that the decreasing agent gets in between cracks and crevices in the case. Use sufficient degreasing liquid since insufficient amounts will be ineffective. Then, allow the decreasing agent to soak for about 30 minutes before proceeding. 

Step 2-Rinse off the De-Greaser 

The next step is to rinse off the de-greaser using a water hose with a high-pressure nozzle. Thoroughly rinse the case and the cylinder plus other engine areas that might have come in contact with the degreaser. 

Step 3- Scrub the Surface 

Using a scrub brush with warm soapy water, scrub the surfaces to the engine casing and cylinder to remove oil stains, grease, grime or other residues build-up. When you’re done with scrubbing, thoroughly rinse the surfaces again. You can use paraffin to soften and loosen thick oily crud.    

Step 4- Dry the Case and Cylinder   

Proceed with drying the engine surfaces using an automotive blow dry or an air compressor to blow off water droplets still on the motorcycle engine. Then, use a lint-free dry towel to dry the surface of the engine. Once you’re done, leave the engine to air dry for about 40-50 minutes. 

Finalizing Cleaning 

After the engine has completely dried, the next thing you should do is to power it up and let it run for a few minutes to blow out any remaining moisture. Then, switch off the engine and let it cool. Once the engine has cooled, the next step is to apply rubber seal protectant on hoses, wires, plastic shields and the fittings on your motorcycle engine. Rubber seal protectant such as the 303 Aerospace Protectant are great for motorcycle engines to make the engine components clean and durable. 

Next, you would want to apply polish chrome to add shimmer to your motorcycle engine. Use a dry clean soft towel to apply the chrome polish. Ensure you buff and polish the surface of the chrome for some few minutes to attain a high gloss shine. If your engine is pretty oxidized, you are unlikely to attain the high gloss shine. Nonetheless, we’ve provided tips below on how you can still get your motorcycle engine to have a deep shimmer. 

When you’re done with all this, remove the plastic bags and masking tape that you used to cover the sensitive engine parts/components. You are now ready for a ride.    

Polishing and Buffing the Engine Case Steps

Attaining that deep liquid shimmer with a silver appearance on the engine shimmer is the dream of every motorcycle enthusiast. There are various ways you can polish your motorcycle to attain a deep sparkle. You can either use a buffing wheel or fine-wire brass brushes attached on a cordless hand-held drill. When polishing aluminum, it’s vital that you avoid scratches or gouges on the surface. You therefore must ensure that you use slow-fine wire brass bristles of 4” and no more than ½” wide to clear scale and oxidation.

  • Blending

The first step in polishing in cleaning as we’ve discussed in the better part of this guide. Ensure that the engine is spotless. The next step after cleaning is to remove deep scratches and marks. You can easily do this using an air-powered angle grinder attached with a Scotch-Brite® type pad. The pad is applied on the area around the scratch or mark to blend it away. 

  • Wet/Dry Sanding 

The next step is sanding using a relatively coarse grade of wet/dry paper i.e. 220 w/d. Use the paper with warm soapy water for excellent results. Frequently clean or wipe the engine case to remove dust or any dirt particles. Next, move on to 400 w/d, 800 w/d, and finally 1, 000 w/d to get a fine uniform finish. After sanding, clean the entire engine surface before the next step which is buffing. 

  • Buffing  

Prior to buffing, ensure that the engine case is extremely clean and free of grit or grease as these will add scratch to the surface. Also, follow the safety precautions which include wearing a face shield plus a recommended eye protector. Make sure you firmly hold on the engine case before applying it to the spinning wheel. Move the engine case slowly but continually over the wheel until the case starts getting hot. Next, use a clean dry towel to polish off the surface oxides residue which appear black and then allow the case to cool. You can also cool it with cold water from a running tap.  After you’ve completed buffing, apply a quality polishing compound of your choice to make the engine case attain a shiny glamor. 

Final Thoughts 

Cleaning motorcycle engine should be a DIY project to save you a couple of bucks. It’s also fulfilling as you get to learn more about your bike. It’s important to clean your motorcycle engine to maintain a high-performance level as well as prevent the build up of grease and dirt which puts your bike in bad shape. Most importantly, clean the engine correctly by following the steps outlined in this guide. 

Click Here to Leave a Comment Below 0 comments