help with a lx 172

[zlock24]

i recently purchased a lx 172 for $100. I knew it needed work. So i need your guys help. The previous owner had fooled with the wiring and screwed it up. the only way I can get it to turn over is cross the hot from the battery to a little tab (Were a wire should hook into, but like i said he messed with the wires) I also replaced the ignition coil, and its got a spark. but it still wont start. So tell me what ive not done? please help me with what step i should take next

 

[Eric Barney]

Start by searching for a wiring schematic. If the harness has been damaged, you might find a good used one on ebay. The safety systems that prevent accidental starting or running: Seat switch, brake switch, PTO switch. All will need to be checked for turn key starting....

Engine has spark, but still won't start? Chances are good that the fuel system will require a thorough cleaning. This is assuming that it (The engine) has compression.
Fuel might not even be getting to the carburetor. Plugged filters, bad fuel pump, etc.