Will a harley soft tail run with a bad ignition module?

Answer 1

It totally depends upon what is wrong with the ignition module. The ignition module's job is to know when the correct time is to send current to the ignition coil. This is what generates the "spark" in the plugs. If the module is not sending current to the coil, no spark, and thus no go. If the module is sending weak current to the coil, the spark will be weak, and that will lead to poor starting, underpowered performance, unburned gasoline getting to your exhaust, and other nastiness. If the ignition module is not firing at the correct time, then that is even worse; that can lead to pinging, knocking, incomplete combustion, lack of power, burned up pistons. Ignition modules also can become "heat" or "cold" sensitive, where they will run intermittently or not at all when they have warmed up, or when they are cool. So, the short answer is "maybe, but it isn't good."