2009 Kawasaki Ninja 650R — Owner's Manual
Drive Chain: The drive chain slack and lubrication must be checked each day before riding the motorcycle, and in accordance with the Periodic Maintenance Chart for safety and to prevent excessive wear. If the chain becomes badly worn or maladjusted - either too loose or too tight - the chain could jump off the sprockets or break. Chain Slack Inspection: Set the motorcycle up on its side stand. Rotate the rear wheel to find the position where the chain is tightest, and measure the maximum chain slack by pulling up and pushing down the chain midway between the engine sprocket and rear wheel sprocket.
If the drive chain is too tight or too loose, adjust it so that the chain slack will be within the standard value. Loosen the left and right chain adjuster locknuts. Remove the cotter pin, and loosen the rear axle nut. If the chain is too loose, turn in the left and right chain adjusting nuts evenly.
If the chain is too tight, turn out the left and right chain adjusting nuts evenly. Turn both chain adjusting nuts evenly until the drive chain has the correct amount of slack.