No spark.

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Jan 18, 2004
I hope everyone has been having a good summer so far. My '72 Roadster ran well for 700 miles then died (cut out at a light and would not restart) on my way home from work the other day. At this point I have no spark and the bike has been converted to a Boyer. Now the monkey wrench in the wheel; When it first broke down and I removed the plug to check for spark, I woulld operate the kick starter by hand and get a strong and long ( in duration) blue spark. Kick it again and again - nothing! Then, unexpectedly, another strong spark. Then - nothing. Put simply, a single firing of the plug out of maybe 15 kicks. Boyer problems? Where should I start. All help is always appreciated. Thanks!
When you have a problem like you have now, it is great if you have the luxury of 2 or more bikes or a good friend willing to let you use his components.
Then you can replace parts until you find the "bad" one.

But this does sound like the Boyer box has died on you. I would "borrow" one & start there.

I have an old box that does the is cactus.

Good Luck.
Thanks for your reply. As of tonight I know the Boyer box is bad. How? I had my son kick the bike over while I checked for spark at both plugs. It was dark outside so I would clearly know if the bike was getting good spark. The spark was intermittent once again. However, to add a little excitement, smoke began rising from under the fuel tank as the Boyer unit burned up! Why did this happen? Was it wrong to have both plugs out at the same time to check for spark? Now I'm worried that I'll put a new Boyer on and burn it up too. Any suggestions?

When a Boyer fails all you can do is sit on the side of the road and think about fixing it, meaning you better get another ride home for you and your Boyer equiped bike.

When problems occur with a points and condenser system, you have repair options. Even on the side of the road there is a good chance you will be able to make a repair that's at least good enough to enable you and the bike to limp home. You can probably guess where I'm going with this, so I won't even say it.

Now if you do decide on another Boyer, double check all wire connectors and look for possible ground faults prior to installation. A volt/ohm meter works great for this. If all electrical connectors are sound and there are no ground faults, just hook up your new Boyer per the instructions that came with the unit and you should be good to go, until next time...

Best regards,


It would appear you may have had a wire/s possibly shorting/grounding somehwere close to the boyer box.

Having the two plugs out would not damage it. With the boyer system, they both fire at once anyway.

You can buy the box only

It is a good idea to tape up all your connections with colour coded tape when you replace the box.(Red or positive, black for neg)
Also, replace the spade connectors with ring connectors where they connect to the coils. & they shouldn't come off.

I had one norton for 6 years with the same boyer & no problems with the box.

You set em & forget em. Beats points anyday from my experience.
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