I use Sea Foam in the (non-ethanol) gas for all my small engines and swear by it. Here is what I use in my diesel fuel ...
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Sea Foam makes the blind walk and the lame see.
I never used Sea Foam in Diesels but I do use a biocide, typically Biobor, to prevent microbe growth at the fuel-water boundary and I use Diesel Purge if I suspect injection issues. The biocide is most important if old fuel doesn't get used up, like tractors off season. The Diesel Purge works best full strength (like filling the fuel filter with if when replacing the filter) but my Kioti hasn't needed that treatment.