Outboard power packs supply high voltage power to the power coils of the outboard's ignition. There are a variety of issues that could cause your engine to intermittently start or not start at all. Any fault at the ignition's power pack lies among the many possible causes of your start-up problems. But because of the power pack's varying voltage, you'll need a peak voltage adapter to determine if the power pack is at fault.
Plug a peak voltage adapter into a multimeter. Match the adapter's black and red connectors to the black and red lead terminals on the multimeter.
Plug the multimeter's test leads into the terminals on the peak voltage adapter -- match the black lead to the black port and the red lead to the red port.
Power on your multimeter and then set the meter to "DC Volts" or "DCV."
Touch each of the multimeter's leads to the ends of the orange wires, running from the power packs to the ignition coils -- touch the orange wires with the positive lead and touch the negative lead to the negative terminal (-) on the ignition coil. You should receive a reading of at least 150V.
Disconnect each orange wire. Connect the wire to the base of a load resistor. Test the load resistor's positive and negative terminals with the positive and negative terminals of a multimeter. If the voltage is still low, then you'll need to replace your outboard's power packs.