Re: Please Help!! No Spark!!
No fire at all:
Disconnect the black yellow kill wire and retest. If the engines now has fire, the kill circuit has a fault-possibly the keyswitch, harness or shift switch.
Check the stator resistance. You should read approximately 500 ohms from the brown wire to engine ground.
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).
Check the timer bases resistance from the black/white wire to the white/black wire. Reading should be 10-20 ohms.
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 trigging 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.
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 the internal wiring (A thin spot in the insulation on one wire).
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.
