boyer box interminent

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Feb 20, 2008
Twice in the last two months I have broke down(unheard on a british bike I know) but I fixed it, I thought it was my plugs because no spark, fuel there, compression there but no spark did the jump the wire between the stator wires in the points cover trick with plug out and it sparked.
My question is are these boyer known for interminent problems like this when they get hot, because if this is the case I will go back to points.

It seemed after I waited about a half hour I had spark.

The Boyer does have a few known potential problems (wire to stator board connections for instance), but all in all has certainly proved to be a reliable and relatively inexpensive ignition system.
Intermittant electrical problems can have you tearing your hair out in short order. My suggestion is to carry a jumper wire with you, something that will reach from Neg battery terminal to the white Boyer box feed wire. Next time it happens (no spark) install the wire, this will by-pass the ignition switch, kill switch, fuse, every wire and connection in the wiring harness. If spark is re-established then you'll know its something besides the Boyer. If spark is still missing then you'll have to look further into the ignition system, good luck.

I have used Boyers for over 20 years. While not the most state of the art, they have been reliable to me. I had one failed pickup wire (after 15 years of use) and one failed black box. I'm sure there are better designs out there now, and the RITA has served me well on E-starts, but I would never go back to points.
Coils are more sensitive to overheating than the "black boxes" are, typically.

Loose connections invite intermittent issues.
Boyers are OK if you take care with connections. I suspect you have loose (dry solder joints) at the timing pick up plate. These are common with age, vibes and heat. Re-do them, ideally direct solder the wires to the rear of the plate and zip tie the 2 leads to the plate.

Don't go back to points - theres too many good reasons for electronic ignitions - Boyer, Pazon, TriSpark are all well proven and durable products.

That's good advice from all.

I now feed the system with two hot wires independent of the kill switch--my wiring never shorts but sometimes just dies. I hear there's a time-out issue with the black box on Nortons--if it doesn't detect make/break in the points cover after a minute or two it goes to sleep. That may explain why your bike restarted after half an hour.

One way to test the box function approximately is to put a voltmeter lead on the first coil being fed (typically the right-hand terminal of the right-hand coil) and kick it through with the ignition on. If you don't see a stout 8-9 volts flickering on and off your box is probably on the way out.

Despite the anecdotal evidence and apocrypha black boxes do die--sometimes by inches until they stop working altogether. Bad feeds and grounds, bad coils and pickup connections are more likely to be the root cause of failure but the box cannot be ruled out. Best of luck

Tim Kraakevik
'72 Combat
Thanks for the replys all connections were good

I come to the conclusion that it was the black box so I am going to order a new one and keep it in my saddlebags, I might try actually tie strapping the new one in instead of just wrapping in rubber and leaving it loose between the frame members under the tank, I know it cant go anywhere but the slight movement of the box didnt do it any favours.

The conections may be good but the wires havn't turened to crap were they go through the timing cover have they, the copper wire just turns to a crumbly mess inside the insulation, good battery?
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