I've got a 1992 idi which I have run many tanks of bio diesel in the last 14 months. just change your fuel filter soon after switching. as for the natural rubber lines, they should be ok as long as there is no considerable seepage so that the stuff gets on the out side and eats away at it. I use either B 50 or less made out of waste vegetable oil. If you can get stuff made out of soy oil, that would make it burn better. if your idi is not turbo'd, it will not burn the bio diesel as good cuz it takes more oxygen and boost to burn that stuff.