If it was cranking but no spark I'd think points/condenser but since they swapped a solenoid it may not have been cranking and then I'd look at the safety switches. The Onan electrical manual is posted in the manual section but not the Kohler.
JB had a no start issue awhile back there's lots of good info in the thread.
http://www.mytractorforum.com/showthread.php?t=211186
That red kind of gets in your blood and pushes the green right out don't it.
Not a bad looking little tractor and definitely a deal with the blower.
To much shadow in the pic but it looks like there could be a holding valve?
JB had a no start issue awhile back there's lots of good info in the thread.
http://www.mytractorforum.com/showthread.php?t=211186
That red kind of gets in your blood and pushes the green right out don't it.
Not a bad looking little tractor and definitely a deal with the blower.
To much shadow in the pic but it looks like there could be a holding valve?