Why can't i get a spark?

I have an MTD millenium ride on mower which ran when I bought it but now I can't get a spark out of it. I've put a new condenser on it but still no spark. According to a chap who looked at it for me (but has since died suddenly!) the wiring has been burnt. it looks as if it's been in a fire under the bonnet. I have taken all the wiring off it and left myself with the two wires which go into the flywheel (they go behind the starter motor) and I thought that if I connected them together it should complete the circuit but that didn't work. Anybody got any ideas?