Re: 1974 Evinrude 70hp Died
You would need some special equipment to test the pack. Here's some troubleshooting procedures:
Johnson/Evinrude Troubleshooting
Alternator Driven CD Ignitions
1972-1978 Engines
(With screw terminal type power packs)
Two Cylinder Engines
No Fire at All:
1. Disconnect the black yellow kill wire and retest. If the engine's ignition has fire, the kill circuit has a fault-check
the key switch, harness and shift switch.
2. Check the stator resistance. You should read approximately 500 ohms from the brown wire to engine ground.
3. Check the DVA output from the stator. You should have a reading of at least 150V or more from the brown
wire to engine ground (while connected to the pack).
4. Check the timer bases resistance from the black/white wire to the white/black wire. Reading should be 10-20
ohms. Note: The original factory specifications was 8-14 ohms, this was changed around the mid to late 1970s.
5. Check the DVA output from the timer base. A reading of at least 0.5V or more from the black/white wire to the
white/black (while connected to the pack) is needed to fire the pack. If the output is low, you may try to reset
the air gap between the timer base sensor and the triggering magnet.
a) Loosen the two mounting screws on the sensor and the nut located in the epoxy on the outside of the
heat shield of the timer base.
b) Slide the sensor in toward the crankshaft approximately 0.005 at a time.
c) Coat the face of the sensor with machinists bluing or equivalent.
d) Install the flywheel according to the service manual and crank the engine over.
e) Remove the flywheel and check to see if the triggering magnet struck the sensor face.
f) If the ignition fired, finger tight the nut on the outside of the heat shield and coat it with RTV.
g) If still no fire, slide the sensor in another 0.005 and repeat steps c through f.
6. Check the DVA voltage on each trigger wire to engine ground. You should have a reading of at least 150V or
more from the black/white wire and the white/black wire to engine ground (while connected to the pack). If the
reading is low, disconnect the trigger wires from the pack and recheck the terminals on the pack. If the voltage
jumps up to an acceptable reading, the timer base may have a problem in its internal wiring (A thin spot in the
insulation on one wire).
7. Check the cranking RPM. A cranking speed of less than 250-RPM will not allow the system to fire properly.
No fire on One Cylinder:
Either a faulty power pack or ignition coil normally causes this. Extremely rare causes include a weak trigger
magnet in the flywheel or a timer base.
Three Cylinder EnginesNo Fire at All:
Note: If the ignition only fires with the spark plugs out, the timer base is likely weak or the engine is not
spinning fast enough. See # 6 and #8.
1. Disconnect the black yellow kill wire and retest. If the engine's ignition has fire, the kill circuit has a fault-check
the key switch, harness and shift switch.
2. Disconnect the yellow wires from the stator to the rectifier and retest. If the engine fires, replace the rectifier.
3. Check the stator resistance. You should read approximately 500 ohms from the brown wire to the brown/yellow
wire.
4. Check the DVA output from the stator. You should have a reading of at least 150V or more from the brown
wire to the brown/yellow wire (while connected to the pack).
5. Check the timer bases resistance from the black/white wire to the white/black wires. Reading should be 10-20
ohms.
6. Check the DVA output from the timer base. A reading of at least 0.5V or more is needed from the black/white
wire to the white/black wires (while connected to the pack) to fire the pack. If the output is low, you may try to
reset the air gap between the timer base sensor and the triggering magnet using a Sensor Gap Gauge (553-9702)
or use the following procedure outlined below.
a) Loosen the two mounting screws on the sensors and the nuts located in the epoxy on the outside of
the heat shield of the timer base.
b) Slide the sensors in toward the crankshaft until the sensor touches the stop boss located at the base
of the sensor mounting area. Tighten the mounting screws.
c) Coat the face of the sensor with machinists bluing or equivalent.
d) Install the flywheel without the key and rotate the flywheel at least one full turn.
25
Johnson/Evinrude Troubleshooting
Johnson/Evinrude Troubleshooting
Alternator Driven CD Ignitions
1972-1978 Engines
(Three Cylinder Engines with screw terminal type power packs, continued..)
e) Remove the flywheel and check to see if the triggering magnet struck the sensor face. If it did, back
the sensor out approximately 0.005 and repeat steps C, D and E.
f) If the ignition fired, finger tight the nut on the outside of the heat shield and coat it with RTV.
g) If still no fire, replace the sensor.
7. Check the DVA voltage on the black/white wire to engine ground. You should have a reading of at least 150V
or more (while connected to the pack). If the reading is low, disconnect the trigger wires from the pack and
recheck the black/white terminal on the pack. If the voltage jumps up to an acceptable reading, the timer base
may have a problem in the internal wiring (A thin spot in the insulation on one wire).
8. Check the cranking RPM. A cranking speed of less than 250-RPM will not allow the system to fire properly.
No fire or Intermittent on One Cylinder:
1. Check the timer base resistance from the black/white wire to the white/black wires. Reading should be 10-20
ohms.
2. Check the DVA output from the timer base. A reading of at least 0.5V or more is needed from the black/white
wire to the white/black wires (while connected to the pack) to fire the pack.
3. Check the DVA output on the orange wires from the power pack while connected to the ignition coils. You
should have a reading of at least 150V or more. If the reading is low on one cylinder, disconnect the orange
wire from the ignition coil for that cylinder and reconnect it to a load resistor. Retest. If the reading is good, the
ignition coil is likely bad. A continued low reading indicates a bad power pack
