I have taken a Boyer Mk 3 system out of my 72 commando and replaced it with a Tri Spark as I was having an intermittent misfire issue and the Tri Spark has a some diagnosis ability .
I have followed the diagram the only issue being the I could not find a white/yellow wire so I used a white/blue wire as had been used on the Boyer by the previous owner .
I cannot get the bike to fire up I have had a couple of pops out of it !
The light on the stator unit goes on and off with engine rotation but the Red ( charge ) light stays on permanently , I know it used to go out as you rotated the engine .
It all looked so simple , any help would be appreciated
WY (white/yellow) from the handlebar switch becomes WU (white/blue) under the tank, so it sounds like you are on the right track there.
Here are a set of wiring diagrams for the Tri-Spark - this should guide you through wiring it correctly:
In addition, I think it is beneficial to wire in an extra positive feed back up to the coils.
I have provided more information about my logic behind this recommendation here in this article:
Does the test button on the Tri-Spark function correctly?
- Take both plugs out and rest them on the engine
- Press and hold the little test button on the unit
- Turn on your ignition switch
- Let go of the test button on the Tri-Spark
- The red light will come on and the spark plugs should both pulse rapidly for 10 seconds
This will confirm that your wiring is good.
If it is, start thinking about the rotor behind the Tri-Spark - is it seated correctly and not slipping, is it done up properly and close enough to the ignition unit etc...
i have a tri spark on my commandos would double check wiring diagrams fist can be found on trial spark web site, as for red charge light this only goes out when bike is running on my bike, i also had problems with some spark plugs which would not fire I'm using ngk bp 7es, and using 6 volt coils, and make sure battery is charged, if you need any help you could email me and may be able to exchange phone no, so i could send pictures of my wiring set up.
Thanks for information and offers of help .
When I get chance I will double check wiring and try running the test .
Hi Grant, I have just finished installing a Try Spark Ignition system-on my 1975 Commando.
When i removed the Boyer Ignition I also had only the blue and white wire to connect to the Tri Spark. I don't think it makes any difference if you use a white wire or a blue and white wire as they are both controlled by the ignition switch.
I also had trouble starting the bike after installation. And would only get a few pops.I started the process of installing the Tri Spark again paying particular attention to the Timing Marks.
Using position B on the stator Module for reference and positioning of the magnets is a good starting point
I then used the two tests with positive results, I then started the bike with no problem. However when I used the strobe light I found that I was considerably out on the timing marks.
On trying to adjust the stator Module to give the correct timing on the strobe light was quite difficult as a small movement of the Module made a lot of difference to the timing.
using the instructions for setting the static timing I did not have enough adjustment on the slots,
So I had to reposition the magnets to obtain the correct timing on the strode light.
I cannot Describe the difference the Tri Spark Ignition has made it is so easy to start and runs so much smoother, once sorted I am sure you will be pleased.
According to the MK3 factory wiring diagram, there is no WU (white/blue).
It should be WY (white/yellow) from the handlebar switch right through to the ballast resistor (which you get rid of when you fit electronic ignition).
Truth is, I have seen some bikes with WU (white/blue) at the ballast resistor, so it suggests to me that there was some inconsistency there during the course of MK3 production.
There are quite a few little errors like that (most of which I try to correct in my diagrams, if they are consistently different to the factory drawings).
The white wire is a hot wire from the ignition switch, so you would be bypassing the kill switch on the handlebars if you use that instead.
The Tri-Spark is a great unit, and certainly my favourite by far. Lack of backfiring is peace of mind for the electric start, and the idle stabilisation works superbly well. Plus I really like the test button and little red LED - it’s all well thought out.
Hopefully you will get the problem sorted. Llike Grant I,ve found the Trispark to be an excellent unit with a great advance curve, idle stabilisation and minimal power requirements. As he mentions in his informative article the earlier versions were susceptible to overheating but the latest Classic Twin version is a big improvement. I also extended the red earth back to the battery and think the bad earthing through the pillar nut or poor connections via the kill switch may be have been the cause of other non heat related problems especially on pre Mk3 models.
On my Mk3 I set it up as per instructions using the crankshaft slot on the righthand side with the O.E. 28° static timing, same as on my old Boyer Micro Power. Trispark recommend 29° which should be OK. I,ve never strobed it to check but everything points to it being spot on and it fired up first time.
My first Classic twin unit from 2011 suffered very high temperatures on a 2015 trip to the south of France. Possibly through cities in heavy traffic during 30°c + summer weather. It eventually failed in 2016 but I managed to get home. Temperature strips showed over 110°c on the unit and 101°c on the cover. It was replaced free of charge by Trispark despite being out of warranty, typical of Steve Kelly,s superb customer service.
The replacement unit has seen temperatures of 100°c on the unit and 80°c on the cover but still performs perfectly after 15,000 miles. Wouldn,t use anything else.
Thanks for all comments and suggestions .
Confession time ! I couldnt find a mistake in the wiring so went back to basics .
Yes I had used the wrong timing mark , when unit was re set correctly it started easily .
Will have to learn not to try and do a job quickly !
Last week I removed the stock regulator, rectifier, capacitor & zener diode. This was replaced with the pricey Tri-Spark option. I had already fitted the Tri-Spark coils and electronic ignition a year or so ago so I decided to stick with the same brand. In for a penny.... After some harness tidying up I kicked her over. This is the best it has idled ever, and it has been laid up for some time. Just need relief on lockdown and the weather to improve to do some running at speed. I was always messing with the carbs to get it idling well (Amal idle circuit cleaning mostly). But I am thinking the fine tuning focus should have been the electrical system?
Hi, I am currently looking for a Commando. The few I have followed up on, so far, have had Boyer's ignition fitted. I've read the Tri-Spark is superior. Is there any reason to avoid the Boyer version / should I budget to replace? Thanks.
I,ve used an early red box Boyer Micro Power for a few thousand miles. It came with a dedicated twin outlet 0.6Ω micro coil and performed very well indeed. Pretty sure it had idle stabilisation. I set it up as per instructions to 28° on my Mk3. No idea what the Boyer Mk3/4 types are, possibly analogue
Replaced it with a Trispark for the compact size, easy wiring and better advance curve, both perform similar but the Boyer pickup not as strong under 4000rpm though some may not even notice.
I had a direct comparism on the 2800 mile Austria Rally when the early model Trispark cooked itself and I refitted the Boyer before the trip. Performed faultlessly in the high temperatures encountered during the 18 day ride with similar overall fuel consumption to what I would get using a Trispark.
If you buy a Commando with a Boyer Micro Power I would leave it installed unless it has a problem. Boyer customer service is excellent like Trispark
Thanks for the advice.