I saw an older thread here re: biodiesel. Been 5 years since the last post, so I thought I'd start a new thread.
I've been running pure biodiesel in my 670 for close to 20 years. The only problems I've had were with the fuel hoses and fuel cap gasket.
It took about 10 years for the BD to turn the rubber hoses to goo. After that I switched them out for urethane. Those lasted maybe 5 years, so now I'm on to neoprene.
Other than that, Yannie runs great, and I'd rather breathe fryer fumes than dino soot. ( The tractor has a stack on it, and at 6'4", the exhaust comes out right at my face level when I'm in the seat.)