Using sewing machine oil like JUKI NF7 to clean a 4-stroke motorcycle engine is not recommended. Sewing machine oil is specifically formulated for lubricating sewing machines and may not have the necessary properties to effectively clean and protect a motorcycle engine.
For cleaning a motorcycle engine, it is best to use an appropriate engine cleaner or solvent designed for that purpose. These products are specifically formulated to break down dirt, grime, and oil deposits commonly found in engines. They have the necessary cleaning agents and solvents to remove contaminants and restore engine performance.
Using the wrong type of oil or cleaner on a motorcycle engine can lead to inadequate cleaning, insufficient lubrication, and potential damage to the engine components. It's always best to use products that are specifically designed for the intended purpose to ensure optimal results and protect the longevity of your motorcycle engine.