Re: 73 Johnson 125 w/ no fire
Rick... The 1972 125hp Johnson has what is called "Battery Capacitance Discharge" ignition, meaning that it is dependent on having 12 volts supplied to it from a battery.<br /><br />Pulling the main electrical connector apart on that model eliminate all voltage being supplied to the powerpack etc!<br /><br />You can test the powerpack as follows, and if you should need a new pack and cannot locate one at a reasonable figure, contact me at my address below.<br /><br />The following may give you some insight on your problem:<br /><br />(Battery Capacitance Dischage Powerpack Test)<br />Various OMC Engines - 1968 to 1972)<br />(J. Reeves)<br /><br />Purchase a small 12v bulb at your local automotive parts store (the 12v bulb is to look like a flashlight bulb, not a headlight bulb). Solder two wires to that bulb, one to the side of the bulb (ground), and the other to the positive point. <br /><br />Remove the spark plugs. With the key in the on position, make sure that you have 12v going to the pack at the terminal block (purple wire). Now, connect the ground wire from the bulb to any powerhead ground. Connect the wire from the positive point of that bulb to the powerpack wire that is connected to the coil wire on the terminal board (blue wire). <br /><br />Crank the engine and observe that bulb closely (CLOSELY!). If that bulb glows even the slightest bit, the powerpack is okay. It may be a very dim glow... just so it glows! If it doesn't glow, the pack has failed. <br /><br />Keep in mind, that type powerpack (Battery Capacitance Discharge) demands a top notch battery of at least 70 amp hours. Any less will, in time, cause powerpack failure.
