First, disconnect the main key switch (if applicable). The key switch, in the off position, grounds the ignition (black lead at the ignition coil). A defective switch can ground out this lead.
Next disconnect the kill switch (if applicable).
Still no spark? My next move is to test for spark using an external power source. Specifically 2 D cell batteries connected in series to provide 3 vdc. A little solder, jumper wire and an alligator clip (and of course Duct Tape). Here is a picture:
- 3vdc power source
Step 1: Leave the main key switch and kill switch disconnected.
Step 2: Remove the spark plug and lay it on the cylinder while still connected to the coil. Make sure that the plug is grounded to the cylinder. Use a wire jumper if necessary.
Step 3: Insulate the points. Use a strip of paper or business card.
Step 4: Connect the negative lead of your 3vdc supply to the stator (ground).
Step 5: Tap or scratch the positive lead of your 3vdc supply at the points wire connection. Each tap will provide a spark at the spark plug.
If you are getting spark by tapping at the points wire, then connect your switches one at a time. Turn the key to the on position and re-test for spark. If spark is still good, then you have a bad set of points OR your exciting coil is open. It is the exciting coil that the 3vdc supply is mimicking. Note that a grounded exciting coil would keep test spark from happening.
If you do not get a spark from your points wire then move your tapping to the condenser. If nothing, then disconnect your terminal plug going to the ignition coil and tap the connection going to the ignition coil (black wire). If still nothing then move your power supply test leads (both positive and negative) clear up to the ignition coil itself.
Note that the only thing necessary to create spark is your ignition coil and spark plug (including the plug wire and cap) If you can not generate a spark by tapping black lead at the coil itself, then the problem is either the ignition coil, the plug wire, the plug cap or the spark plug itself.
If you find that you can generate spark at the coil but not with the stator connected, then standard isolation trouble shooting applies. The best reference that I have found is found beginning on page 71 of the Official Hodaka Workshop Manual (Wombat and Combat Wombat).
I hope that this information is found useful. You can verify an ignition coil on the bench with just the coil, spark plug and the 3vdc battery pack. Use test leads to tie your spark plug ground to your coil ground and the negative lead of your power source. Pretty simple and effective!
Dale
Victor
