I have a kohler 5E marine generator It will blow the input fuse when cranking. If the voltage regulator is disconnected it will start but only run if the start switch is pressed. Any Ideas?

I have the same genset. Just fixed a similar prob with it. Mine would intermittently blow fuses at first then started blowing them as soon as trying to start. I also saw a puff of smoke from reg when it did run at one point. Carefully check stator wires for shorts to ground. Make sure to lift the stator wires that are grounded in control box. If no grounds replace control board and reg board. $400+. Cross your fingers and try it. Mine worked, thank God. The pc boards are marginally designed and built. The relays, diodes and other componants are way too undersized for the application and can not survive a lot of cycling
on and off. When starting genset make sure to slowly apply loads to it. Same thing when shutting it down. Dont shut it down with any load. It wont take it
Good luck