I'm having a problem with my craftsman LT1000, (917.271653 B&S eng 310707) lawn tractor. It cranks but will not start. Fuel selnoid is working fine. Spark can be seen from the plug when cranking. Spraying starter fluid in the carb or directly into the spark plug opening (plug reinstalled) has no effect. Valves adjusted to spec and operating normally. Compression is 90PSI cold and comes up quickly. Governor appears to be OK. Any suggestions?? Would really appreciate some help. Thanks in advance.

OK. After hours of troubleshooting my lawn tractor that wouldn't start, I found the problem. The key in the flywheel had split causing the flywheel to rotate out of position just enough to cause the spark to occur later than normal. Because the spark was occurring much later in the cycle, the fuel in the cylinder couldn't ignite. I replaced the flywheel key, re-adjusted the intake and exhaust valves and the engine started normally. I thought I would post my fix to assist anyone who may have a similar problem. Now, time to go out and cut the grass :(