Model 40 crawler won't start

[odinrp]

I recently purchased a Model 40 crawler and it ran great for about a week. Then one day after running for a few hours I turned it off. Now it will not start or even turn over. I cleaned the batt. terminals and tightened and then checked for charge. OK. I then checked for electricity at starter moter. OK. Somehow the starter will not engage when the knob is pulled out. It always started before with one try. How do I check to see if it is the starter or an electrical problem. Is there a fuse? Can I cross wire it to start or at least find out if the starter motor engages?
Any help will be appreciated.
Odinrp