This Race Preparation and Tuning Manual from Team Yamaha was published in 1984 and was designed as a guide to set up a Yamaha Motocross Bike for Race Day, it covers everything from how to properly set the Suspension, Carburetor Tuning, how to check a fouled Spark Plug etc.
This Manual may come in use for you as similar Pre-Race Procedures are still used today, otherwise it could be an interesting piece of Racing History to add to your collection.