low end noise ??

[maddoggy]

I've noticed that when my k5 is sitting at idle rpm it has a low rumbling,rattling sound in the bottom end. I can't hear it at all when its throttled up. a riding buddy told me that he has heard other kx's making the same noise and he thinks it's no big deal. I'm not so sure. any thoughts? thanks in advance.

[hughes]

KIPS valves rattling? Or maybe it's time for new 0-rings and crush washer for the your pipe. Check your pipe springs.