I can not get my Gravely 144Z 19HP mower to start. I was cutting along just fine and it just shut down. I checked the seat swtich, parking brake switch, and the connections under the key switch. Everything appears fine but I must be missing something because now it will not do anything. I had to loosen the hydralic bypass to push it back into the garage where it now just sits. Anyone got any ideas, tips, tricks, experience with this problem?