CDI Electronics Outboard Ignition Troubleshooting Guide

42 TROUBLESHOOTING GUIDE - Johnson/Evinrude Troubleshooting Johnson/Evinrude Troubleshooting Three Cylinder Two Stroke Engines 1979-1988 60-75 HP Models Service Note: Please use the Factory recommended spark plug (currently Champion QL77JC4) gapped at 0.030”. NO SPARK ON ANY CYLINDER: 1. Disconnect the Black/Yellow stop wire AT THE POWER PACK and retest. If the engine’s ignition has spark, the stop circuit has a fault. Check the key switch, harness and shift switch. 2. Disconnect the Yellow wires from the rectifier and retest. If the ignition now has spark, replace the rectifier. 3. Check the cranking RPM. A cranking speed of less than 250-RPM will not allow the system to spark properly. This can be caused by a weak battery, dragging starter, bad battery cables or a mechanical problem inside the engine. 4. Inspect and clean all engine and ignition ground connections. 5. Check the stator and timer base resistance and DVA output as given below: WIRE READ TO OEM Ohms CDI Ohms DVA (Connected) DVA (Disconnected) Brown Brown/Yellow 360-440 (9 amp) 530-630 150-400 V (*) 150-400 V (*) Brown Brown/Yellow 750-950 (12 amp) 530-630 150-400 V (*) 150-400 V (*) White Blue 9-21 0.6 V + 0.6 V + (#) White Purple 9-21 0.6 V + 0.6 V + (#) White Green 9-21 0.6 V + 0.6 V + (#) (*) This reading can be used to determine if a stator or pack has a problem. For instance, if you have no spark on any cylinder and the stator’s DVA reading is out of spec – disconnect the stator wires and recheck the DVA output. If the reading is still out of spec – the stator is bad. If the reading is now within spec – the pack is likely defective. (#) This reading can be used to determine if a pack has a problem in the triggering circuit. For instance, if you have no spark on one cylinder and the timer base’s DVA reading for that cylinder is low – disconnect the timer base wires and recheck the DVA output. If the reading stays low – the timer base is bad. If the reading is now within spec – the pack is bad. (a) Check stator DVA first. Then if timer base DVA is 0.6 - 2.5 V, the pack is faulty. If below 0.6 V or 2.6 - 99 V, the timer base is faulty. 6. Check the triggering and charge coil flywheel magnets for cracked, broken and loose magnets. NO SPARK OR INTERMITTENT SPARK ON ONE OR MORE CYLINDERS: 1. Check the timer base resistance and DVA output (see NO SPARK ON ANY CYLINDER above). 2. 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 pack load resistor and retest. If the reading is now good, the ignition coil is likely bad. A continued low reading indicates a bad power pack if the timer base checks good. 3. Visually inspect the ignition coils for burned or discolored areas and cracks in the casing (indicating arcing inside the coil). 4. Swap the ignition coil with one that is sparking correctly. 5. Rare causes include a weak trigger magnet. If possible, try another flywheel. POWER PACK OR TIMER BASE REPEATEDLY BLOWS ON SAME CYLINDER: 1. Check the timer base wires for shorts to engine ground as a shorted timer base wire can destroy a SCR inside the power pack. 2. In contrast, a shorted SCR inside the power pack can destroy a timer base coil. Check the timer base resistance and DVA output (see NO SPARK ON ANY CYLINDER above). 3. Replace the ignition coil on the cylinder dropping spark. ENGINE WILL NOT SHUT OFF: Disconnect the stop wire at the power pack. Connect a jumper wire to the stop wire from the pack and short it to engine ground. If this stops the pack from sparking, the stop circuit has a fault. Check the key switch, harness and shift switch. If the pack is still sparking, replace the power pack.