According to :
I have a 14.5 hp Tecumseh engine on my riding lawn mower -- but no
spark at the plug. After tremendous amounts of troubleshooting I blame
the ignition module. Note: I've disconnected the grounding cutoff
wire, and there are no other wires on the module excpet for the spark
plug wire. My problem: with a spark tester connected to the spark plug
there is only a dim flash of light. However, when I connect the spark
tester directly to motor ground, there is a bright flash! I've changed
the plugs out several times. This sounds to me like the module is
producing a diminished output which is strong enough to light the spark
tester but not enough to fire across the spark plug. BUT....... I had
thought these modules were either totally GOOD or totally BAD, period.
Please, any comments? Am I overlooking something? Note: the magnets
on the flywheel seem quite strong. The air gap is perfect. HELP!!

Sounds like a poor connection on the module. Ie: bad ground.
--
Chris Lewis, Una confibula non set est
It's not just anyone who gets a Starship Cruiser class named after them.