I have a 1970 Commando with the same problem. Boyer EI and a power box. Originally it was only firing on the left side, replaced everything coils plugs wires, reset timing nothing changed. Finally checked the Boyer box and found a small crack in it. So I upgraded to a newer version and away it went. It ran well for a few weeks then it started doing the same as yours. Kicks backyes I checked and set the valve clearance previously. I use a very thin guitar string to clean the carbs and followed bushman's site it's very good.
I haven't had time today to push start the bike but I will post the outcome it ASAP
thank you all
I was advised to run 12v coils with the Boyer EI.
I ran a pair of Lucas 12V coils for years with a Boyer MkIII ignition. No problems starting or riding. I thought I read both 6V and 12V coils are supported in the Boyer documentation.
Note the number of threads above the jam nut when you check/set the clearance. I'm thinking that, given the symptoms you described initially, that one or more of the valves may not be seating.I will check the carburetors and the valves again! just to be sure
Migsan, not sure if this was already suggested, but did you also swap out the stator plate? All Boyers have a common issue which is exasperated on the Commando. The wire strands break inside the insulation and cause a host of symptoms.The boyer is a new MK4 from the triumph t140. I put the Mk3 aside already!
I will check the carburetors and the valves again! just to be sure
I wasn't able to do it yet because the compression kit hasn't yet arrived but it's on the the list thanks!Suck
Squeeze
Bang
Blow
Certainly, in nine pages of troubleshooting, a compression test was mentioned.
OP, was a compression test performed? Results?
Thanks for the help. I tried changing the stator plate already but I will check for the wires tomorrow to be safe. Today spoke with Boyer Bransden and they also suggested the following: "Migsan, not sure if this was already suggested, but did you also swap out the stator plate? All Boyers have a common issue which is exasperated on the Commando. The wire strands break inside the insulation and cause a host of symptoms.
Cut the cable tie and move the wires, you may feel that they feel more flexible where the tie was, which would indicate they are broken.
View attachment 78930
There are many fixes for the issue, this was mine..
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Almost Stranded
I was a bit bored today, as my kids have gone back home and my wife was at work. Bike riding is out at the moment as there is about 5 inches of snow outside. So I thought what can I quickly do in the freezing garage? Ideally I want to take a bit off the bike and check or refurb it in the house...www.accessnorton.com
Have you also tried wiring from the battery direct to the ignition ( bypassing all the switches and connectors)?
Good luck. Together we'll get you going.
Cheers,
cliffa.
I correct myself I just checked and they are 6volt coils
That would be likey to make things worse (unless one or both 6V coils are faulty).
For Boyer electronic ignition the coils must be connected in series, the two 6V coils, therefore, share the voltage so each is working at around 6V.
Two 12V coils in series also get 6V each so won't give the same output as 6V coils.