Small Engines (Lawn Mowers, etc.): short on Yazoo Zero Turn mower, amp fuse, special circumstance

Question
I have a short that keeps blowing the 20 AMP fuse on my Yazoo/Kees Zero turn. When I ride it (230 lbs)it blows the fuse under the seat. When my wife (120 lbs) it does not blow the fuse. Where should I start. Yazoo/Kees 23 hp Model #zkh61221

Thanks very much Steve Parker

Answer
I think I'd put a couple hundred pounds of weight on the seat and then start checking wires for continuity to ground.  There's probably not any easy way to find it other than that.  A short is hard enough to find, adding this special circumstance is going to make it even harder I imagine.  Wish there was an easy answer.  Thanks, PK.