I'm guessing that it was this way when Pete got it. I never let it idle, just start it up and motor (gently) off.
However it is happening, I'll bet this will stop it.
Some 1/16" Stainless flat stock, a little band saw work, brake, and hammer (V11 content) and dolly.
2018-06-16_02-15-37 by Charles Stottlemyer, on Flickr
I'll bead blast the stand and this piece, mix up a batch of Metal Set epoxy, and squoze it all together. Tomorrow, after the epoxy cures, I'll take a die grinder to it and make it look a little less crude.