Partee217.... At some point in all the above, you mentioned replacing the powerpack and also mentioned low voltage being supplied to the coils. That indicates, usually, a failed or failing "Charge Coil" that supplies the needed voltage to the powerpack capacitor.
The ignition and electronic unit under the flywheel of that model normally consists of the "Powerpack", "Timing Sensor", Charge Coil", and a "Two Coil Stator".... If your unit is different, let me know.
Now... Disconnect the battery before doing any of the following. One sparking event would be expensive!
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If memory serves me right, read on:
The "Timing Sensor"... The ohm reading between the disconnected two wires of the "Timing Sensor" on the "Low Ohms" scale would be 40 ohms +/- 10 ohms..... then using the "High Ohms" scale, check for shorts between either wire to ground. What did you get?
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The "Charge Coil"... If electric start equipped direct from the factory, the ohm meter set to "High Ohms", the reading between the two disconnected wires of the Charge Coil would be 475 ohms +/- 75 ohms.
If equipped with only "Rope Start" from the factory with the electric start installed at a later date... the reading would be 575 ohms +/- 75 ohms. In either case (rope/electric) check those two wires for shorts between the coil and ground.
However... if that black charge coil is melting down... has a sticky looking substance dripping from it, replace it regardless of what reading you might get as that would result in a voltage drop to the powerpack. Let me know what you found with this charge coil.
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Note that a slow cranking engine would result in the flywheel magnets moving at a slow rpm past that charge coil which would result in weak, erratic, or no ignition. I don't recall if that info is listed in the service manuals or not but the average rpm stated is normally around 300 rpm which is always exceeded in yanking the rope thru or acquired via the electric start system.
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The "Stator Assembly"... Supplies AC voltage to the rectifier to be converted to DC voltage to charge the battery. The stator is normally a three (3) wire system, if yours is different, let me know.
Set the ohm meter to "Low Ohms" Have the stator wires disconnected.
Black meter lead to Yellow.... Red lead to Yellow/Gray = .35 ohms +/- .1 ohms
Black meter lead to Yellow.... Red lead to Yellow/Blue = .2 ohms +/- .1 ohms
Change meter to "High Ohms"
Black meter lead to Yellow.... Red lead to Ground = No reading is good .... Any kind of reading is shorted!
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The "Rectifier" Converts AC voltage to DC voltage.
(Small Rectifier Test)
(J. Reeves)
Remove the rectifier wires from the terminal block. Using a ohm meter, connect the black lead of the ohm meter to the rectifier base (ground), then one by one, connect the red lead of the ohm meter to the yellow, yellow/gray, then the red wire (some rectifiers may also have a fourth yellow/blue wire. If so connect to that also). Now, reverse the ohm meter leads and check those same wires again. You should get a reading in one direction, and none at all in the other direction.
Now, connect the black lead of the ohm meter to the red wire. One by one, connect the red lead of the ohm meter to the yellow, yellow/gray, and if present, the yellow/blue wire. Then reverse the leads, checking the wires again. Once more, you should get a reading in one direction and none in the other.
Note that the reading obtained from the red rectifier wire will be lower then what is obtained from the other wires.
Any deviation from the "Reading", "No Reading" as above indicates a faulty rectifier. Note that a rectifier will not tolerate reverse polarity. Simply touching the battery with the cables in the reverse order or hooking up a battery charger backwards will blow the diodes in the rectifier assembly immediately.
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The above takes in just about everything that could interfere with the ignition system (You've already checked the stop button). Hopefully you find the problem with the above tests.