Last year, around 11,000km, my cam chain started rattling. A few thousand kilometers later the noise went away - guess the thing jumped one tooth and stretched the chain again. Well, I've been riding the past 5,000+ km with that damn noise again and I just couldn't take it anymore. So, I got myself a Krieger tensioner...Finally actually!
Since, I've changed the stock bars for a Renthal CR High. I didn't wanna cut the ends, so I just put the perches more to the inside, but still the clutch cable is too tight. I found out in the forums the KLX300's clutch cable will fit. Got one, too, and indeed it's about an inch longer than stock and it's a perfect match to it.
The cable will be mounted tomorrow and I will report back. I will have to take the bike to the dealer to replace the tensioner. No appropriate tools. At least they let me in to watch the work being done to the bike.

 

Spend $10 on a wrench set.

It's an easy and painless job.

Worst part is the tiny space you have to get the wrench in on the left side of the bike.