Cummins 25kw diesel generator only has 614 hours Kubota 4 cylinder engine very compact and in clean shape. Wired for 120/240 single phase.   It could be re wired for 3 phase as well. Would be perfect for a spray drone setup 
If removing from trailer 67 inch long 30 inch wide 57 inch tall
But would have to ad a fuel tank to it since the trailer is the fuel tank