Ticking noise?

[The Ninja]

So I was riding my friend's ninja today, and we had to put it away because it was making this ticking noise. When we ran the engine and gave it a little gas it would tick near the top. I did a little searching around on other forums, but I was curious as to what gearheads on this forum would say. What could it be? Maybe timing chain? And is that an expensive/laborious repair? Could I do it myself with or are there any specialty tools needed? Any help is appreciated.

[Halfwit]

timing chain, could be valves out of adjustment, could be a nut vibrating in the cargo area... never know.

[The_ CaneCorso]

valve adj time...Miles?

[Tarzanman]

.......it could be a few things, but my guess is that the cam chain is getting loose.

Not a problem until it skips timing and (potentially) seriously jacks up the engine.

You want to check the cam chain tensioner. The manual should have the procedure for that bike