Re: 125 HP #1 & 2 Cylinders No Spark
Force Troubleshooting
Prestolite ADI Ignitions 1984-1992
General
1. Check for broken wires and terminals, especially inside the plastic plug-in connectors. We recommend that you remove the
pins from the connectors using the CDI 511-9706 pin removal tool and visually inspect them.
2. Check the flywheel for a broken or loose magnet.
3. Disconnect the stop wires from the CD and connect a DC voltmeter between the stop wires and engine ground, turn the
ignition switch on and off several times. If, at any time, you see voltage appearing on the meter, there is a problem in the
harness or ignition switch. At NO TIME SHOULD YOU SEE BATTERY VOLTAGE ON A STOP CIRCUIT.
4. Visually inspect stator for burned or discolored areas. If found, replace the stator. If the areas are on the battery charge
windings, it indicates a possible problem with the rectifier.
IF THERE IS NO SPARK ON ANY CYLINDER:
1. Disconnect the stop wire AT THE PACK.
2. Check for broken or bare wires on the CD Module, stator and trigger.
3. Check the stator resistance and output using the CDI meter with the 511-9773 peak reading adapter and 511-9770 piercing
probes, as follows:
Read Form Read To Resistance (OEM) Resistance (CDI) DVA (connected) DVA (disconnected)
Yellow Blue 680-850 250-350 180V or more 200 V or more
Yellow Engine Gnd Open Open 180 V or more (a) 2 V or less (b)
Blue Engine Gnd Open Open 180 V or more (a) 2 V or less (b)
NOTE: Remember that the stator may use Brown/Yellow or Brown/Black/Yellow for Yellow and Brown/Blue or
Brown/Black/Blue for Blue.
(a) The DVA reading to engine ground is checking a circuit inside the power pack. If the readings are not fairly equal, swap the stator
wires going to the power pack and recheck. If the low reading stays on the same wire from the stator, replace the stator. Otherwise,
replace the power pack.
(b) Most meters will pick up a small amount of voltage due to inductive pick-up. As long as the voltage is very low, it will not indicate a
problem.
4. Disconnect the rectifier. If the engine now has spark, replace the rectifier.
NO SPARK OR INTERMITTENT SPARK ON ONE CYLINDER:
1. Check the stator and trigger resistance; the trigger wire sets should read approximately 50 ohms between the wire sets
(DVA-.5V or more), the stator should read 680-800 ohms (factory) and 250-350 ohms (CDI/RAPAIR) DVA 180V or more
from blue to yellow.
2. If readings are good, disconnect stop wire from one pack. If the dead cylinder starts sparking, the problem is likely the
blocking diode in the opposite pack.
NO SPARK ON TWO CYLINDERS:
If two cylinders from the same CD unit have no spark, the problem is usually in the stator. Test per above.
ENGINE WILL NOT SHUT OFF:
Check the stop circuit in the pack by using a jumper wire connected to the stop wire coming out of the pack and shorting it to
ground. If this stops the pack from sparking, the stop circuit in the harness or on the boat is bad, the ignition switch could also be
bad.
COILS ONLY HAVE SPARK WITH THE SPARK PLUGS OUT:
Check for dragging starter or low battery causing slow cranking speed. DVA test stator and trigger.
HIGH SPEED MISS:
1. Using the CDI meter with the 511-9773 peak reading adapter, (or CD-77) and 511-9770 piercing probes, DVA check stator
voltage to each pack at high speed. If it exceeds 400 volts, replace the pack.
