Ok. I have a Homelite HT-17 Hedge trimmer that will not hit unless the in line spark tester is attached to the lead and coil. It is sparking without it but will not run. If the inline spark checker is attached it will run like a new one. Any ideas? Thanks guys.
Put a resistor spark plug in there.
Some of the modules are very sensitive to the spark plug and the spark plug gap.
The bigger the gap the more resistance in the circuit.