Determining whether a Harley-Davidson motor has been replaced with another brand's motor would typically require physical inspection, documentation, or information from the motorcycle's owner.
These documents may indicate the make and model of the engine.
Research the model: Familiarize yourself with the specifications and characteristics of the specific Harley-Davidson model in question. This can help you identify any deviations from the original engine, such as changes in displacement, configuration, or design elements.
Examine the engine: Physically inspect the engine for any indications of non-standard or aftermarket components. Look for signs of modifications, such as different branding, mismatched parts, or alterations to the mounting points.
Seek professional assistance: If you are uncertain or unable to determine whether the engine has been replaced, consider consulting a knowledgeable motorcycle mechanic or Harley-Davidson dealer. They may be able to provide guidance based on their expertise and experience with Harley-Davidson motorcycles.
Remember that modifications or engine replacements can have legal and regulatory implications, so it's important to ensure compliance with local laws and regulations regarding motorcycle modifications and engine swaps.