I will assume that when you say "
jumping 2 leads on starter motor " that you mean the BIG red one to the SMALL one. This means that the starter is good.
The keyswitch (when turned to "start") simply sends +12v to that SMALL connector on the starter. You need to figure out why this is not happening.
Most likely the problem is one of the safety switches. All of the safeties must be satisfied before the starter is allowed to crank.
It is easiest to locate a schematic diagram to find out what safety switches are in the circuit.
Then, using a voltmeter, it is a simple task to isolate the problem.
One way to troubleshoot is to clip voltmeter across each safety switch one at a time (wires still attached) If you measure 12v when trying to crank the engine THAT switch is the issue.
A 'quick -n- dirty' way I have used is to, one at a time, TEMPORARILY jumper across each of the safety switches (wires still attached) and try cranking engine each time. If you jumper a safety and the engine cranks, THAT switch is the problem.
I work on small engines several times a week. My basic electrical troubleshooting gear consists of a voltmeter and a 2 foot wire with clips on each end. I can diagnose a lot of problems with these 2 items.
Some of the safety switches may be:
- Clutch disengaged
- PTO disengaged
- Brake pushed
- Operator in seat
- etc... Different machines have different switches