Engine Noise

Can worn valve guides cause a ticking/knocking noise when the engine heats up? I have been chasing this noise for sometime now and can't figure it out. The valves are all set to within spec, cam chain tension is good and the timing is on. In the morning when it is cool there is no noise, or when you first start up the bike but as it gets warm on the ride home (temp 29C/85F) the noise can be heard. Any help is appreciated. Thanks!

Without hearing, it's difficult to say but perhaps it's premature ignition. Try some higher octane fuel or if already running highest, try retarding timing a little.
-Duck

Yeah, what Duck said. It sounds like pre-ignition. First step is a tank of higher octane gas. However, you might want to check the plugs first. Do a throttle chop when you've got it warmed up and making noise. Then pull your plugs (do all four, just in case) and check with
Dan
Go down to page 61 for an explanation, then check on page 62. By the way, lots of stuff to learn there, so don't stop with just reading your plugs.
The likely possibilities are lean mixture or too much advance/not enough octane. Learning to read your own plugs is much better than taking the advice of somebody who isn't there, and won't be there if and when it breaks down.