I have a 2003 Exmark Lazer Z with a 27 hp Kohler. The PTO switch came apart so I replaced it. After that the clutch fuse kept blowing. I replaced the clutch and cured the fuse issue. Now when I release the parking brake or engage the clutch it kills the engine. I have bypassed the mercury tilt switch. The seat switch, brake switch, motion control switches test good. What next?
Both of those symptioms suggest a problem with the seat safety switch.
Most newer mowers use relays so if you just pull the plug they will not work.
You could also have a bare wire short in the safety circuits.
These are all ground circuits so if one is grounded when it should not be it can be hard to find.