Cub Cadet GT1554 keeps blowing fuse when starting--Any ideas?

i have a propane powered buffer 12 volt electric startwith a kawasaki 17 hp engine and i turn the ignition and the fuse blows i have changed the regulator the selonoid,starter battery ignition checkrd the wiring and i keep blowing a 20 amp fuse

Dustin
July 2007