Late last season after no issues, my diesel Kohler 3.5EFOZ/4EOZ generator would crank but not start. I chalked it up to the trash in the fuel tank that I polished out and so this spring I changed both the bowl pre filter and the steel cased generator mounted filter. After giving the battery a good charge, and bleeding the air out per the manual, it continues to crank without starting. It's got a functional fuel pump as it's spraying when bleeding the air. Thinking that maybe it just needed to be cranked for a bit, I did 5+ attempts of 15 sec cranks...still nothing. Any ideas?