My 10HP has no spark at the plug. I've replaced the points, twice, replaced the condenser, and retried the old one, replaced the coil, run a jumper wire from battery to + on the coil, and combinations of all. Still no spark. Kinda running out of ideas.
So lets get back to the basics, grab a 12v test light, hook the lead to ground, place the tip of the test light to the coil (-) and it should turn on and off repeatedly as you crank the engine. If it does, then the problem is the coil, plug wire or plug. If it does not turn on the light, check the (+) side of the coil. If it is lit all the time whilst cranking then either it is the coil or the wiring to the points or improperly adjusted/assembled points. (pay attention to the placement of the coil wire to the points, on some if the wire is in the wrong place like under the screw head and no insulator then you effectively created a dead short to ground. If it is not lit (+) then you have a power supply issue to the coil.