I have a 15.5 HP Sears Craftsman 42" riding lawn mower that shuts down when I release the clutch OR engage the blade. Starts and runs fine, but engaging blade OR releasing the clutch to go shuts her down. HELP!

I'm betting that you need a new safety kill switch - probably the one underneath the seat (the spring-loaded plunger switch that won't let you use the machine without your *** in the seat). Could also be the one behind the "dash" that is associated with the blade engagement mechanism.

I know that the under-seat-switch cannot be bypassed or it will disable the machine in the exact way that you described. Why do I say this? Because I just tried to bypass my own "***-in-the-seat-safety-switch" on my very own 15.5 HP, 42" Sears tractor, and it responded by punishing me - the absense of the switch caused the motor to cut out when I tried to put the machine in gear AND/OR engage the blade. It seems to have some measured capacitance - the absense of same seeming to interrupt the ignition timing enough to shut the motor down when you attempt to get anywhere past neutral or engage the blade. These "safety" switches may be needed by a very few who prefer to be drunk while they mow lawns on steep slopes that their tractor mowers were not designed for, but I find these items to be troublesome and enfuriating. My trees shed a lot of sticks in high winds, and I can't stand shutting the machine down and restarting it EVERY SINGLE TIME I have to dismount to clear sticks or other obstructions out of my mowing path. This is an obnoxious, "nanny-design" feature that desparately needs to be discontinued. It also makes both jump-starting the tractor and electrical troubleshooting much more difficult than they should be. The tractor should let you dismount without shutting down, as long as you have disengaged the blade and shifted into neutral. It should also let you jump start with jumper cables - impossible to do with your rear end in the seat. By the way, call Manufacturer's Supply, Inc. at 1-800-826-8563. They may have a replacement - their item number 31-9664 might do it, but talk to them first. I'm calling them tomorrow. Good luck.

Ck the seat switch