How do you tighten the cam chain on 2004 400ex?

To tighten the cam chain on a 2004 Honda 400EX, first, remove the left side engine cover to access the cam chain tensioner. Loosen the tensioner bolt and turn the adjusting screw clockwise to increase tension on the chain. Once adjusted, re-tighten the tensioner bolt to secure the setting. Finally, replace the engine cover and ensure everything is properly secured before starting the engine.