Hi Guys,
A friend of mine recently bought a boat with a early 90s 75 hp, 3 cyl Mercury oil injected motor. The starter wouldn't work properly, and we tracked it down to the starter solenoid. Other than that, the boat ran great during the test drive. After procuring the part, my friend changed the solenoid. During the repair, he decided that he didn't need to disconnect the battery and in the process arced the positive battery cable across several of the ignition components, disabling the ignition system. Another friend took a look at the boat and concluded the CDI box was bad. The original buyer ordered and installed the new CDI box, and the boat started at the house. He took it to the lake, and no spark again. At this point, I was asked to help out.
Using the references I could find online, I tested the coil packs (primary and secondary), trigger, and stator for impedance. The stator tested bad (blue to engine ground was open), so we ordered and installed a used stator. No change. The used stator tests good for impedance, but I'm not getting any voltage to the red lead during cranking and around 15 volts to the blue lead while cranking. The voltage to the yellow wires at the rectifier is 11.6V prior to cranking, and 6.3 volts while cranking. The voltage going to the CD switch (? 2 red leads going out from starter solenoid, and 2 yellow, 1 gray (tach) coming back to rectifier) is 12.6V. The boat has a new key switch and throttle assembly. There are three batteries ran in parallel to the engine, so battery power shouldn't be an issue. The rectifier impedance test was questionable (if I did it correctly, it failed). The black/yellow kill wire at the CDI box is working properly (the wire is reading open to ground with the key on, and 0 to ground with the key off). The starter seized up as I was testing other components/voltages, so no more tests until I get it rebuilt/replaced. I'm at a loss as what to do next, and the budget doesn't support changing parts just to change parts. Any and all help is appreciated!
A friend of mine recently bought a boat with a early 90s 75 hp, 3 cyl Mercury oil injected motor. The starter wouldn't work properly, and we tracked it down to the starter solenoid. Other than that, the boat ran great during the test drive. After procuring the part, my friend changed the solenoid. During the repair, he decided that he didn't need to disconnect the battery and in the process arced the positive battery cable across several of the ignition components, disabling the ignition system. Another friend took a look at the boat and concluded the CDI box was bad. The original buyer ordered and installed the new CDI box, and the boat started at the house. He took it to the lake, and no spark again. At this point, I was asked to help out.
Using the references I could find online, I tested the coil packs (primary and secondary), trigger, and stator for impedance. The stator tested bad (blue to engine ground was open), so we ordered and installed a used stator. No change. The used stator tests good for impedance, but I'm not getting any voltage to the red lead during cranking and around 15 volts to the blue lead while cranking. The voltage to the yellow wires at the rectifier is 11.6V prior to cranking, and 6.3 volts while cranking. The voltage going to the CD switch (? 2 red leads going out from starter solenoid, and 2 yellow, 1 gray (tach) coming back to rectifier) is 12.6V. The boat has a new key switch and throttle assembly. There are three batteries ran in parallel to the engine, so battery power shouldn't be an issue. The rectifier impedance test was questionable (if I did it correctly, it failed). The black/yellow kill wire at the CDI box is working properly (the wire is reading open to ground with the key on, and 0 to ground with the key off). The starter seized up as I was testing other components/voltages, so no more tests until I get it rebuilt/replaced. I'm at a loss as what to do next, and the budget doesn't support changing parts just to change parts. Any and all help is appreciated!