I have a 42' 17hp Murray riding lawn mower with the Briggs & Straton engine that will not start. I replace the armatuer and both spark plugs and still nothing. The engine is getting gas and is turning over but it still will not start - any help would be great.

Armature, like the starter? Was the starter not truning the engine over? Sounds like it does. Bench Testing a Starter Motor (http://www.misterfixit.com/starttst.htm) Do the plugs get a good blue spark? Remove a plug, reattach the wire and ground it to the block. Try to start and see if you have spark. If not, check the safety switches starting with the one under the seat. I would suspect no spark and it can be caused by a safety switch malfunction.