The term "157 FMI" is not directly associated with a specific motorcycle engine. It appears to be an alphanumeric code that does not correspond to a widely recognized engine designation or model.
In general, motorcycle engines are identified using different naming conventions depending on the manufacturer and model. Engine designations usually consist of a combination of letters, numbers, and sometimes additional characters to indicate various specifications such as engine size, configuration, features, or modifications.
To determine the specific details of a motorcycle engine, it would be helpful to refer to the manufacturer's documentation, website, or contact the manufacturer directly for accurate and reliable information regarding their engine models and specifications.