Mine didn't make any noise for quite a while. I am thinking that the bolts loosend off a bit. I am doing the bike tube vibration damper modification solution also known as the BTVMS.:)

After giving my plate a big hit on a rock it started vibrating, I took it off and straightened things up and tightened it up properly, no more noise.

Mine is all fixed now. I wrapped the forward bars that the plate connects to in silicone fusible tape (a.k.a. "Tommy Tape" http://www.tommytape.com/). I also cut gaskets out of 1/8" silicone slabs to put on either side of the bolts up against the plate. It works perfect and no more buzzing.

Hmmmmm this is a very interesting thread. I also have that irritating buzzing sound. I always thought it was the Valves floating in the motor. Well now I too will have to do the removal test. Thanks man. If this is it I will buy you lunch....for real. ;)

I never really had a prob with noise from mine.. Weird..

But I DO have a prob with mud NOT coming out from inbetween the skid plate and bike.

So the other day I took a couple 1¼" hole drills and put a hole in each "wing" and one in the center.. NOW it drains properly!