The specific turning angle for the front forks of a Harley Davidson Sportster XLH883L may vary depending on various factors, including the specific model year and any modifications made to the motorcycle. Therefore, it is best to consult the owner's manual or contact a Harley Davidson dealership for the most accurate information regarding the recommended turning angle for your particular motorcycle. They will be able to provide you with the specific details and adjustments that are suitable for your bike.