Re: 1972 85 hp evinrude
Weak spark, any kind of spark would indicate that the amplifier (Pulsepack) is operating, but that some other component (coil) might be breaking down. You can check the amplifier as follows:<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. You might use a bulb of a somewhat lower voltage to obtain a brighter glow... just a suggestion.<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.
