When to replace 400ex chain

[grancuda]

How do you know when to replace the timing chain on a 400ex? I just bought a 400ex and it is making a little cam chain noise. I reset the chain tensioner and it was quiet for about an hour. Not sure if I need a tensioner or a chain.

[rob_990]

how old is it? did you check the valves? if you did your most likely gonna need a new chain.id recommend one from a crf450