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Motorcycle Repair/1963 Honda c110 50cc Primary coil


How do you check the primary and secondary coils in the ignition to see if they are still good? thanks! Ron.


Check out the wiring diagram at

If the inside of the flywheel/rotor is nice and clean where the magnets are, you should be able to see volts coming out of the stator leads, testing it with a small 6/12v test light or a meter, when you spin the motor over.

To test them individually, you would have to dismantle them from the backing plate, isolate the ends of the coils from ground and test for resistance and for grounding to the coil mount. They are just coils of copper wire, but they must be insulated from each other and not grounded to the mount internally. When installed, one end does go to ground and the other one out to the rectifier and/or the ignition secondary coil, depending upon what coil it is. Most common "no spark" problems are dirty/worn points, points not adjusted properly and a bad condenser.

Bill Silver

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Bill Silver


Need help with vintage Hondas from the 1960s? I am an expert with 250-305cc bikes in particular and most all of the other pre-91 models, in general. I do NOT claim to have a great deal of experience on Gold Wings, Cruisers, ATC/ATVs and dirt bikes.


I have owned/ridden/maintained Honda motorcycles for 35 years. I have written five books on Honda repairs and collecting. I was a service manager for two Honda shops back in the 1980s.

VJMC (Vintage Japanese Motorcycle Club) of North America

VJMC newsletter, as editor for two years and as contributing editor currently.

3 years auto shop in high school, teacher's aide in Automotive Technology in Jr. College, Diesel mechanic course in college, self-taught mechanic and automotive writer.

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