Here's how to check the drive belt tension on a Harley Davidson motorcycle without any special tools. Harley recommends that you buy a special tool to check the drive belt tension on your motorcycle, but if you don't have the tool handy, this method is fairly accurate, and it will let you know if you need to tighten or loosen the drive belt on your Harley-Davidson. It's simple, and you can do it in under a minute. Just put the motorcycle in neutral, grab the belt an inch and a half behind the primary cover, and twist it with 2 fingers and a thumb. It should feel really tight when the belt is twisted 45 degrees. If you can't twist the Harley's drive belt 45 degrees, it is too tight. If you can twist it more than 45 degrees, it is too loose.