Help please, no spark on my new 71 commando

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Jan 15, 2005
I just picked this bike up at an auction today, the first Norton for me. I'm not getting any spark when kicking it over. However, it does give me a nice spark each time I turn the key from one position to another, is that normal? It has a boyer ignition apparently. I wasn't sure where the key should be until I spoke to the seller, who said all the way clockwise. (I did check for spark with the key at each position though) He said there's no kind of kill switch, just the key. According to him, it starts one or two kicks reliably. I'm figuring there's just something I'm not thinking of. I've already bugged him quite a bit getting the price down & such (It didn't meet his reserve with the bids), I really feel bad pestering him any more. Any help would be greatly appreciated.
I am guessing that your spark is at the plugs. If so........
It May just be in the "Lucas" switch, have you tried fiddling with the switch, it sounds like you have. Mine has to be "just right" the poc.

Maybe try bypassing the switch to rule it out of the equation :idea:

Debby should be good at working this out by now, you may hear from her.
Someone else said "the majority of electrical problems are bad wiring." I think that's true. The Lucas ignition switch has a high failure rate also. A wiring diagram, a VOM, and some jumper wires should help track the problem down.

OldBritts has a Boyer troubleshooting guide on their website. Go to, navigate to Technical Articles, scroll down to Electrical & Electronics. Apparently it is normal for the Boyer to generate a spark when you switch the ignition off.

I bypassed the switch & didn't get any spark, so I went through all the wiring connections related to the ignition & got it to start up. It runs superbly until it gets hot, then stops altogether. Did that twice. I had a boat do this to me, it baffled me endlessly until I replaced the coil. I do think I'll plan on rewiring everything soldering as I go & using heatshrink. I'll let you know if a new coil solves this. Thanks for the help!
'71 ignition

If you think you have a shorted coil, put a plastic bag around each and put them back in the brackets. Lucas coils are known to short if clamped too hard. The bag will insulate any internal short from the bike's ground. Try running again.
If you discover it isn't the coil/s, it may a good idea to "borrow" another boyer "black box" next, assuming you have good connections at all your ignition points, including the "infamous" break down in the points housing & where they exit.

It should still run on one if it is "A" coil..........................

Good luck & at least you are developing skills to fix it on the road if need be.
I purchased a new coil (bike had the one 12V coil set up along with the boyer stuff) I got one with a 5 ohm resistance as the Boyer system specifies. I printed some install instructions & trouble-shooting guide & have gone through both checking everything out & still no luck. -The trouble shooting guide states that if I get a spark when turing off the ignition or by disconecting either stator wire that the black box and the wiring is ok. This leaves the stator as the likely suspect I think. I pulled it off & found a bit of chalky white deposit on each magnet. I gently cleaned that off, replaced the stator plate (I marked it's position) but still nothing. Any way to determine if the stator assembly is bad? -What about the wire braking problem that I see in the other thread? If that were my problem I'd not be getting the single spark when disconecting one of those wires right? -I'm also having computer problems so I can only check in here every few days, but I definately do appreciate the ideas.
Now this may sound strange since your plugs are making spark outside the head but it wouln't be the first time. Go find a nice new set of Autolite AP64's Spark plugs. Put them in just how they come gap .035. Before you buy anything else. Was the coil you bought a single coil with dual output? Because if your running a pair of coils with a Boyer they should be 6 volt not 12 as you stated. The single coils are two 6 volts wired internal. norbsa just try it these plugs work.
Well, I'm a bit in disbelief norbsa. I tried a set of those autolite plugs & got a spark via the kicker. (It was only making spark when turning on or off the ignition, not from kicking) That's the good news, and thank you very much by the way. Now, here's the bad: I broke one of those timing plate set bolts. :evil: Same story as it always is "The bolt isn't bottomed out yet, it's still turning too easy. I'll just keep going.... *@$%!!!
I'll order a couple from old britts. In the meantime, I'll ride the triumph down to sears when it opens & get some reverse drills & easy -outs. And maybe a rubber mallet for my head. I figure if I get that one out I can find another bolt to hold the stator plate down & the timing cover will be ok with just the one bolt for a ride around the block or two.
Agree with the other suggestion.....if a spark results when you turn the key, the contacts in the switch might not be clean and making bad contact. I have had my switch apart at least ten times, they get moisture in them , it corrodes the contacts, or the soldered connections in there get broken. If you rule out all other posiblities, then mark and remove all wires from the back, check the wires themselves, get out the book and see which wires go to which accessory, and then use a volt/Ohm meter to check that the switch makes a good connection from say , the ground, through the switch, towards the park light, head light, and ...yes...the ignition. Unless you are like me, and will take "Anything" apart, best to get another one if you find some connection bad. Mine has been soldered so many times inside...there a springs and a ball bearing in there too. You CAN take it apart, you have to bend the crimps in the housing out of the way back there, so you can remove the Bakeolite disc with the bayonet connections from where it sits in the back of the housing, but it is a job for either a careful and methodical person, or...maybe a watchmaker. I have done it many times, but then again....I take the electronic stuff apart on the car too, and not everyone is cut out for that sort of recklessness.
Just reread all the entries.....hope you get the bolt out, it's kind of small for a drill and remove action, I had it happen in 74 and since then I have been rather careful about those funny looking screws. All in all, it sounds like you have a broken connection somewhere, bet you find a broken wire, or dirty connection somewhere. Every year I have something like that, last year it was a rear brake light switch that somehow sent all the power to ground when I used the brake,....must admit though, the battery was 8 years old and didn't give enough power to the Boyer, so the Boyer died from not having enough current every time I used the brake. Boyers need a good battery....if there isn't enough power to make the headlight bright when you turn it on( with the motor off), then the Boyer won't start the bike.....also something to look at. It was though.....very exciting to go into a corner and lose the motor a few meters before the curve. Took the switch apart and fixed it...problem gone. Be patient with your bike though....despite all this trouble, it will turn out to be more fun to ride than any of the rice burners......the Norton just isn't for everyone though, you have to enjoy tinkering...
Ok, she runs again, but here's sumthing else wierd. It's giving me no advance at all, except during the period when the revs drop as I let off the throttle. also, I must be getting a pretty weak spark in one plug, because the timing light won't work off of that one. (but if I pull the plug wire, the revs drop, so it's getting something at least.) Boyer instructions say to set the spark at 31 btdc with the revs above 5000. I have a shop manual on the way, but it's not here yet. to set up the timing initially boyer has you work off the 31 degree mark, which leads me to believe that the unit doesn't give spark advance, but it simply retards the timing at low rpms instead, is that correct? Either way it doesn't seem to be doing it.
Check all those connections plugs, plug wires, check all is hooked up correctly, because there is some reason that on one side the timing light doesn't see enough spark to make it light up. Not sure how the Boyer works, but wouldn't worry about setting the timing until both plugs fire properly.
As to the timing...I set mine in 75 or so...and it is still correct. Quite a trick it the lady doesn't stay still at over 5 will wander across the pavement, so I needed 2 fellows to hold it down while I set the pickup disc at the right place. Ove the years, the solder joints on the pickup tend to break, the place where the wires come out of the back of the timing case is another "wear" point...dirt gets into all connections...check these places out, something is causing the spark to be weak on that one side..
To my experience, the black box either works, or stops completely...
I've lost two or three over the years, and they are filled with a black, hard carbonlike stuff that won't let you get at the electronic components to replace them, so you have to buy a new box when they break. But you know it when they break, the bike goes dead as a half dead about it. Best to have a spare if you plan to go coast to coast.
So I would look at wiring, check the coils to make sure there is no reading (Ohm) between the innards and the case, etc.
Good luck...keep at it, you will find the problem be ever so surprised how "Simple" it should have been to find and life will be wonderful!
Just wondering if your battery in a good state of charge ?

I also read somewhere that you can set your Boyer @ 21 degrees @ 2000 rpm. Supposedly this is for "new" engines so you aren't revving them too much when new.
Static timing it should be good enough to solve the problem you are having though.
I just had the same problem with my 74 Norton. Turn the key on and off and on again the plugs would spark. No spark from the kick starter.

The problem was a broken wire at the black ty-wrap on the stator.

The resistance across the blk/wht and blk/yel wires when disconnected from the Boyer box is about 160 ohms.

I've had this problem before. it's a pain in the arse. So much so that I made a test box with an LED that I can hook up to the wires from the stator. when I kick the the kick starter the LED will flash if there is voltage from the stator.

I've also connected a function generator to the input leads to the black box to test the iginition system from the stator to the plugs. If you do this, make sure to remove the plugs from the head so you don't blast that last bit of gas in the cyclinder. Ask me how I know. I purchased two of those test plugs with the clamps that you can get at the auto parts store.

If memory serves me it seems that the output voltage from the stator is around 170 millivolts or so.
Thanks for the continued help guys. I have checked the resistance of the stator, it's right at 160 & doesn't move if I wiggle the wires or anything. -I'm not imagining this, it's DEFINATELY advancing the timing only as the revs drop. It runs lovely & timing stays steady as a rock at 31 degrees while the revs climb up to 3K or so (I don't dare to go higher while this is going on). The instant I back off the throttle, the timing jumps up to about 40 degrees, it backfires through the pipes and dies. Anyone ever heard of anything like that? I'll go through all the wiring again this weekend & get into the other stuff that I don't think has anything to do with the ignition for good measure. -I aught to get my shop manual tomorrow or Friday also.
This all sounds rather strange....sure you got all the wires in the right place? My memory isn't what it should be, but I remember that the firing point had to be set at 31 or so BTC (and some machines had two different timeing the right one?), so the spark would be that far advanced when the motor was almost redlining.....and that the sparking point fell off when the revs were lowered. Sort of like you "Maxed" the box out for a certain engine speed and the box took care of sending the spark at the right time for the rest of the running range...if you get what I mean.
Never seen an advance system that started so far advanced (31)at an idle anyway...unless I've not paid attention, and what machine would start at that kind of an advanced spark...lord knows...maybe a Norton. If your timing is jumping up to 40 or so and you haven't even reached the magic 5000 setting point...then what will it be at 5000? Either it wasn't set to 31 at 5000 rpms, or something is working rather backwards...are the cables to the black box switched around? Or the cables that come from the distributor switched, they are hard to see being black/yellow and black/white, and I'm not sure it would make a big difference, but they may be marked for a reason. Do you have a good set of instuctions for this Boyer or are you just going by what the previous owner had hooked up....I still have my original instructions and would be happy to send a PDF if you need them...there is info in the instructions about differences between building years and the different wiring they used. Let me know. As I said before though......Harrison was right and indeed "All things will pass".
Here's a long shot

Could it be you have the wrong rotor? Or maybe the center piece of the rotor has come loose from the magnet. The would place the timing marks in the wrong position in relation to the crank, and this relationship could change with speed.

I seem to remember seeing a rotor with "grooves" that could be mistaken for timing marks on the back side of the rotor.

Like I say, this is a long shot.

Good luck
The timming problem you are having stems from reversed stator leads. You have to keep them straight or the Boyer will go nuts. See troble shooting guide in Walridge Motors catolog. Norbsa
Ok, here's an update. I checked those stator leads to see if I had 'em swapped, but they're yellow - yellow & white - white at both connection spots (down at the stator & up by the box). I swapped them for the heck of it & it wouldn't start at all like that.
-About the advancing on deceleration- what's actually happening is that the timing is retarding instead of advancing as the revs climb. What I was seeing was the timing returning back to it's idle state, which I must have had over advanced in order for it to run at higher rpms once the box was retarding the timing. I guess maybe I never saw the whole scenerio because I can't reach the throttle & see into the sidecover at the same time. (The bike's got a mikuni with the cable pulling straight out the top, no handy throttle lever on the carb) I also checked the other ignition related wiring again & it all seems in order according to the wiring diagram(s) I've downloaded. I don't have the original boyer paperwork to go by but I've searched quite a bit & found two seperate trouble-shooting guides as well as two wiring diagrams. I think now that it'll actually start I aught to try my triumph's battery in it again and maybe the old coil that I had replaced but didn't need to. What about the alternator? Could it cause the ignition to act funny if it wasn't working up to snuff? Or would that only come into play if the battery was low or bad?
I'm not getting frustrated at least. If I actually get some time to spend out in the garage it's a good day, so no big deal.
Hi Mrblisters,
You wrote awhile back that you had bypassed you ignition switch. I have to ask did you also bypass the kill button on the handlebar? If you did not do yourself a favor and run a jumper wire straight from battery negative to the white (power in) boyer wire. This will completely eliminate any questions about the bikes wiring. I don't know if your up on the concept of voltage drop, but, if you checked for voltage at the Boyer feed wire by disconnecting it, it may read 12V, but, if the ignition switch, kill switch, or any bullit connectors in line are dirty that 12V won't be there when the circuit is actually working.
Justa thought,
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