Small Engines (Lawn Mowers, etc.): Tecumseh 17.5hp, head bolts, head gasket

Question
I have a Huskey lawn tractor with a 17.5 Tecumseh. It will not start. I have replaced the carb float bowl, magneto, spark plug. It has spark. I've tried to pour gas into the carb and it will still not fire.Could this be a timing problem ? Any help would be great as I do not have an owners manual. Thank you.

Answer
 Hello Mike:

 The timing is set by the Flywheel Key. Do a Compression Check. The Head Gasket may be Leaking. Check the Torque of the Head Bolts (75ft pd). The Valves May Need to be ReGround and Lash Set. Other than the Carb needing Cleaned and Overhauled, that is all I can think of that would cause the Problem. Hope this Helps.

 Good Luck

 Respectfully

 John