Motorcycle Repair/1963 Honda C110
QUESTION: Hello, I had no spark. New points etc. I ended up repairing the stator by unwinding about 10" of copper wire I injured removing the flywheel with a puller. I finally got a good spark and the bike started right up after sitting for about two years. I cleaned gas tank etc. I have no key, no battery etc. but the bike always ran until no spark issue.
I usually kill the engine with the choke but yesterday used the ignition switch and shorted it on the frame to kill the engine. The spark from the short was larger than expected and since then, no spark at the plug. The plug is fine. Could I have damaged the coil by creating a spark/short when I killed the engine? When I fixed the stator, I put polyurethane on the wire and re would the 10" when the poly was "tacky" to avoid and cracks. I covered the winding with liquid electric tape and like I said, got a great spark and the bike ran fine.
What damage did I do when I shorted the ignition to the frame to cause this problem again? HELP. Thanks. Mark M, Buffalo, MN
ANSWER: Mark, the ignition is magneto, so shorted primary windings from tool damage makes sense. Perhaps, your wiring repairs have shorted out now. The ignition switch grounds the ignition normally, so turning the switch to OFF and grounding it (if I understand what you stated) to the frame shouldn't make much difference, but the arcing might have caused some kind of back EMF energy that whacked the windings.
Test the primary wiring first with a test light or volt meter on AC volts and see if you still have some juice coming up from the magneto, itself. If so, then check the second half of the system... wiring to the ignition coil. You might have caused some kind of damage to the condenser, too. The system is setup for minimum arcing normally.
Test the primary windings of the coil to see if you have around 5-8 ohms impedance. I don't have coil specs on the AC magnetos, however.
I assume you have no lights on the bike now. Running w/o a battery will kill them, if that is the case.
---------- FOLLOW-UP ----------
QUESTION: Hello Bill, Thanks for your reply. I have a couple of questions. I'm not sure how I test the prim85gnoary windings on the ignition coil. Also, is there a way to check the condenser with a multi meter or if not, are they a common condenser I could buy at NAPA or some similar place? I appreciate your help. I am in the process of repairing the stator again just in case there was a EMF (not sure what that means) issue with the windings I repaired. Thanks very much for the help. Mark M.
Mark, you need a volt/ohm meter to test the primary resistance. Set the meter on a low scale and attach to the two small wires on the coil to get a reading.
For the most part, a condenser is a condenser although the do have slightly differing microfarad ratings. The tricky part is to get it all nestled in with the points and field coils beneath the rotor/flywheel.
(truncated search results from eBay - do a "HONDA C110 or C100 condenser search for current results you can see there are various types with and without wiring leads. Most have to be soldered into place, but Honda used components from Nippon Denso and Kokusan which designed them differently.
It appears that you need the one with the wire in it, according to:
EMF is electro-motive force.... a measurable wave of electrical energy.