I've never tried a broom stick.

Right now its running on D2 with a splash of Stanadyne. Its MUCH quieter on B100. Tons.

WINGAS as the main feedstock for our bio is literally chicken wing fryers. Our bio doesn't cloud like normal bio does; the chicken fat forms little balls! ( I never push the mix when it starts getting cold, and clearly, we aint brewing now. Not in an unheated garage!)

I do beleive the MM are on their way out; the motor idles shaky only when hot. I haven't had that trouble much lately as ambients are well below 32f.

No odd metal in the filter btw. Guess they're just LOUD inside.

BTW, I DP'd it and took it around a country block. It runs much easier/quiter on DP. But that whine is everpresent . Its defintely mechanical. Its not what I'm hearing under the valve cover.