I'm starting to notice some slack in the chain on my 2005 400ex. It's the original chain so is it time for a new one? If so, should I replace the sprockets too?

 

You could try adjusting the chain tension. Take a look at the sprockets, are they worn or broken? If not just adjust the chain tension. Keep that chain lubed as well.

 

I would do like bounce and try to adjuist it out first ,but if u buy a new chain change the sprokets as well ,worn sprokets will wear the new chain faster,and unless u buy a cheap non Oring chain the sprokets will be cheaper than the chain

 

Almost 4 years old, replace the chain and sprockets.
Rockymountainatv.com has a good price on a combo with both sprockets and chain.

 

alright thanks for all the help. I'll check that site out...

whats the difference in an x-ring and o-ring chain? gold chain?

 

Chains and sprockets are disposable items, that need to be replaced from time to time. Best to replace all three! It's better than breaking a chain out on the trail!!!

I like DID X-Ring chains and Renthal sprockets. I go aluminum in back, to save weight.