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Motorcycle Repair/ignition pulser generator


My 1982 Honda cb650 Nighthawk just stopped running one day. Thought it was the coil at first but the trouble maker I think is the pulse generator assembly. I was happy to think it was the coils at first because they are easy to replace but the pulse generator replacement is not to be found. Are there any other years that can be used in this application?
Any thoughts on this would be greatly appreciated! Thanks for your time.

Michele, If all the sparks stopped on both coils, then it probably isn't the pulse generator.  #4

That's because you have two coils and two pulse generators. It is highly unlikely that both sides have failed at the same time. Make sure your KILL switch isn't in the OFF position or is having wiring issues.

Check power into the coils on the black/white wires. You should have battery voltage there for both coils. If not, backtrack to the KILL switch wiring. Also check the back of the ignition switch, as they contact plate can work loose and cause partial or total electrical failure.

Other controllers for the spark are the spark modules back by the battery.. #2  These are problematical at times, but can be repaired or swapped out with similar ones from other generations of bikes from that time frame.

If you have lost spark on just one set of coils, then focus on the components affecting that side by swapping leads/components from the other side that is working.

Be sure that you have a fully functioning charging system, as the electronics will start failing when the battery voltage drops down below about 11 volts. The rotors in the charging systems are known points of failure. The H4 headlights draw a lot of current and will suck the battery down quickly when the charging system isn't doing its job 100%.

Troubleshooting info available at

FYI   Ebay number 181635405446   

Bill Silver  

Motorcycle Repair

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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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