FWIW, the biodiesel I'm using is supposed to be comercially produced, ASTM B100.

I showed the filters to one of the injection hut guys (who did not know I was running any kind of alternate fuels), he looked at the guck and immediately said 'rubber'. I asked, "It's not algae?" To which he replied, "Algae is black too but this is rubber."

Now I'm not 100% certain these guys know everything there is to know about biofuels but, they do know their way around diesel engines.

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Never a dull moment at Berry Hill Farm.