I bought this used 1997 model exmark lazer z in October soley for the ultra vac bagger system, I was gonna take the blower and bagger off and put them on my mower. Well I fixed a few problems that it had and have been using it for leave clean-ups. I replaced the pto switch, ran it yesterday 1/2 day, no problems, went to restart it after lunch and nothing, just the carb fuel valve clicking, my brother jumped the solonide and it started right up, I finished my day, today I got it in the garage, new keyswitch, starter off another engine that works, we checked all the safty interlocks, another solonide checked wires, tested the safty module and the engine will not start by the key? What are we missing we put 4 hours in on it, and come up empty. Any ideas?