Small Engines (Lawn Mowers, etc.): 1542hs, battery cables, cable ends

Question
Hello Eric, I have a 1542hs Sabre manufactured by John Deere. I have trouble with starting it. I feel it is an electrical problem, as I can jump start it with my car. I bought a ignition bypass switch which I wired up (15amp)wire and took it straight from positive terminal to the Start switch and from the switch to the Starting motor. Although the engine turned over the wire became hot and started to melt. I did not permanently house the switch, as I was running a quick test,just held it in my hand and pressed it. Can you perhaps shed some light in what I am doing wrong. Kindest regards Jack.

Answer
Will the mower starter motor turn the engine with the spark plug(s) removed?

How old is the mower?  Did the problem occur suddenly or has the mower sat for a while?  Is a push rod bent causing too much compression?  Have you dis-connected the battery cables and cleaned the battery terminals and cable ends with a wire brush?

Let me know.
Eric