Hey!!!,
Below the carburetor, just behind the cylinder, on top of the case, there should be a rubber cap covering the cam chain adjuster. Remove the cap, remove the bolt on the top of the adjuster (10mm wrench), loosen the adjuster lock (14mm wrench), take something small enough to fit in the hole that you took the top bolt out of. You'll feel the adjuster pin, push it in and let it come back out on its own. Tighten the adjuster lock, and re-install the top bolt and rubber cap. The cam tenssioner is spring loaded and semi-self adjusting. If the top end is really noisy, you may want to take it apart and check it out. The cam chains do wear and over time will put your valve timing slightly out. Check the compression, your valves and piston rings may be worn bad enough to make the bike hard to start. It's probably time to re-build it.