Boyer to Tri Spark conversion in progress

Hi All,

I was just about to install a Tri Spark but when I pulled off the points cover I found an old Boyer ignition installed, I was expecting an original Norton ignition and the instructions I have for installation are for an original ignition to Tri Spark. Does anyone have experience with this? It looks like the wiring is quite different to stock and I'm not sure where to begin, I included images of the ignition and the wiring up around the coils.







In other news, it looks like there's traces of oil in the points area which I think may mean that I have a leaking cam shaft seal. Is this a job that I can do myself or does it require a professional?

Any and all advice is greatly appreciated, I bought this bike to learn more about Nortons so I'm all ears.

The oil seal is easy to do and would be best done at the same time as the ignition as you will need to re do the timing.
You will need to replace the timing side gasket.
The seal will push out and the new one pushes back in.
There is a tool to screw into the camshaft, it has a taper which prevents damage to the oil seal.
I replaced mine without, using plenty of oil on the seal, it doesn't leak.
Les emery sells GUIDE - CAMSHAFT OIL SEAL - FOR FITTING TIMING COVER for about £8.
I have a Boyer unit which is perfect if the battery is fully charged!

Cannot see the ignition being complicated but will let someone with experience of the specific ignition give you advice

Thanks Peter, I'll order that seal and gasket now. I'll get the tool you mentioned too.

If you search online you should find the Boyer setup instructions, i would be tempted to make sure the timing is spot on with the Boyer first before removing. You dont say why you are installing a tri spark, is the bike running ok at the moment?

Hey Spelky, the bike is running but not particularly well. I had assumed it might have had something to do with the points ignition but as I mentioned above, I discovered today that there's an oil-soaked Boyer installed.

I've already bought the kit to switch to a Tri Spark and a modern coil set up from CNW and the currently installed parts look much worse for wear. I'll take your advice about figuring out how the Boyer is installed and then see if I can figure out how that changes things for a Tri Spark installation. I had hoped it would be simpler than this but at the end of the day, it's a free lesson in motorcycle electrics!

Branch said:

I'll take your advice about figuring out how the Boyer is installed and then see if I can figure out how that changes things for a Tri Spark installation. I had hoped it would be simpler than this but at the end of the day, it's a free lesson in motorcycle electrics!

Click to expand...

It would be much easier in my opinion if you were to disconnect and remove the Boyer box and pickup, and then wire up the Tri-Spark according to the instructions rather than trying to work out 'points-to-Boyer-to-Tri-Spark'.
Installation of the Tri-Spark is relatively straightforward but I can guide you through it step-by-step if necessary.

Hi Branch, I would go with LABs suggestion particularly as he is offerimg to guide you on the Tri spark set up, what he doesn't know about commandos isn't worth knowing, hope it goes ok.

I must say, I've never had much luck with those pre-insulated crimped terminals in your photos. Is the blue type even the right size for your cables?

I'm not condemning your setup outright. They appear to have been crimped with a "W" type tool, but maybe the second crimp onto the cable's insulation has not been done. Can't tell for sure from the photos.

Hi L.A.B., thanks for your advice, my only concern is that once I remove the Boyer and its box I've have no idea what wire goes where! I'll roll up my sleeves and start the process tomorrow (it's 11pm here at the moment) and when/if I get stuck I'll update this thread with a plea for help and photos of whatever progress I have made. I had done all my research as if I were just doing the points -> Tri Spark conversion so I'll read up more on the Boyer system tonight. Thanks again!

Triton Thrasher said:

I must say, I've never had much luck with those pre-insulated crimped terminals in your photos. Is the blue type even the right size for your cables?

I'm not condemning your setup outright. They appear to have been crimped with a "W" type tool, but maybe the second crimp onto the cable's insulation has not been done. Can't tell for sure from the photos.

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Thanks for pointing this out, I'll have a closer look at them. It looks like I'll be removing those tomorrow to fit the Tri Spark but there might be more elsewhere in the loom. The joys of discovering the previous owner's handywork!

Branch said:

Hi L.A.B., thanks for your advice, my only concern is that once I remove the Boyer and its box I've have no idea what wire goes where!

Click to expand...

Basically, the only Boyer box wire connection you need to concern yourself with is the white (assuming standard +ve earth/ground polarity, as that is the power supply), so make a note of the harness wire it connects to (likely to be either a white/yellow or a white/blue).

Here are instructions I received from Tri Spark when I asked the same questions. I also added their coils and HT leads. The motor now starts a LOT easier, idles reliably due to their idle stabilazation. Good luck!

To replace the boyer you simply remove their pick up and rotor from the engine and the black box from the wiring and start the Tri-Spark installation from there. You will find going from the boyer installation that the coil positive connection and the coil link wire can be retained. The two wires from the Tri-Spark module can then be connected according to the instructions. One will go to the coil negative and the other to the ignition power feed which was connected to your boyer box. It's pretty easy if you know your was around wiring on the bike.

Please let me know if you need anything further,

Stephen Kelly
Northstar Electronics - Tri-Spark Ignition
mob 0414 379 674
tel +61 08 8371 1664
fax +61 08 8371 0839
sales@trispark.com.au www.trispark.com.au
Like us on Facebook (www.facebook.com/TriSparkIgnition)

jamesp said:

Here are instructions I received from Tri Spark when I asked the same questions. I also added their coils and HT leads. The motor now starts a LOT easier, idles reliably due to their idle stabilazation. Good luck!

To replace the boyer you simply remove their pick up and rotor from the engine and the black box from the wiring and start the Tri-Spark installation from there. You will find going from the boyer installation that the coil positive connection and the coil link wire can be retained. The two wires from the Tri-Spark module can then be connected according to the instructions. One will go to the coil negative and the other to the ignition power feed which was connected to your boyer box. It's pretty easy if you know your was around wiring on the bike.

Please let me know if you need anything further,

Stephen Kelly
Northstar Electronics - Tri-Spark Ignition
mob 0414 379 674
tel +61 08 8371 1664
fax +61 08 8371 0839
sales@trispark.com.au http://www.trispark.com.au
Like us on Facebook (http://www.facebook.com/TriSparkIgnition)

Click to expand...

Thanks James! This is very useful.

**Update

Today I've stripped out the old coils, Boyer box and Boyer ignition. Going forward it seems relatively straight forward except for some questionable wiring which I've added pictures of below.





The join between the two red wires (lower right) and the red and yellow wire (lower left) is baffling me a little bit. One of the right-side red wires went to the left coil, and the other went to the Boyer box. Both red wires are joined to a dodgy connector with a red and yellow wire (left side), the red wire goes into the headlight and the yellow wire goes direct to the battery positive terminal.

My concern is that I don't know what is happening with the red and yellow wires, should they be connected to the Tri Spark?

I appreciate any help or suggestions, I'm reticent to charge ahead as I don't want to damage the Tri Spark, they aren't cheap!

Branch said:

The join between the two red wires (lower right) and the red and yellow wire (lower left) is baffling me a little bit. One of the right-side red wires went to the left coil, and the other went to the Boyer box. Both red wires are joined to a dodgy connector with a red and yellow wire (left side), the red wire goes into the headlight and the yellow wire goes direct to the battery positive terminal.

My concern is that I don't know what is happening with the red and yellow wires, should they be connected to the Tri Spark?

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No, just disconnect the Boyer box red and leave the other two reds and the (non-standard) yellow connected as they are, but I seriously suggest you remake any dodgy connections.

L.A.B. said:

Branch said:

The join between the two red wires (lower right) and the red and yellow wire (lower left) is baffling me a little bit. One of the right-side red wires went to the left coil, and the other went to the Boyer box. Both red wires are joined to a dodgy connector with a red and yellow wire (left side), the red wire goes into the headlight and the yellow wire goes direct to the battery positive terminal.

My concern is that I don't know what is happening with the red and yellow wires, should they be connected to the Tri Spark?

Click to expand...

No, just disconnect the Boyer box red and leave the other two reds and the (non-standard) yellow connected as they are, but I seriously suggest you remake any dodgy connections.

Click to expand...

Okay thanks L.A.B., will do this and continue with the installation. I'm going to fix the connections as I go and the longer term plan is to redo the wiring looms with new ones from British Wiring.

Branch said:

I'm going to fix the connections as I go and the longer term plan is to redo the wiring looms with new ones from British Wiring.

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I strongly suggest you renew the black/white and black/yellow wires now, rather than later.
Due to the constant shaking of the engine on the Isolastics, the copper strands can eventually fracture unseen under the insulation in the area where they enter the crankcase-so it would be wise move to replace them as part of the installation process.

Okay time to check back in, the good news is that the wiring is now far neater and everything has been checked with a multimeter. The Tri Spark is installed as per the instructions however the engine won't start, which is frustrating as everything seems to be working as it should.

- I've checked the spark on both plugs and they light up when the rotor spins against the Tri Spark stator and the LED comes on.
- Fuel/Air is on and working, carburettor hasn't been touched since the Norton was running last week.
- I've checked the two wires that lead to the Tri Spark in the timing cover - black/yellow wire is at 12.6 volts.
- All lights and electrical systems work fine and battery is fully charged.
- Plug gaps are as per manual.


When I'm kickstarting the bike the engine turns over with compression as per usual, and I can see the LED on the Tri Spark lighting up as the rotor passes it. I've set the timing to 28 degrees on the primary side as is recommended for the Tri Spark.

I've had a couple of issues, it looks like the rotor on the primary side has two markings at 180 degree intervals. From what I've read one is for TDC and the other is for BDC, I have attached an image of what I can see through the timing cover when the pistons are both at full TDC, I used the marking you can see in the image for setting the timing at 28 degrees.



With the Tri Spark unit, in the instructions it looks like I am supposed to install the white/black wire from the coil to the white/black wire on the Tri Spark, and the yellow/back wire to the yellow/black wire that leads to the positive battery terminal. My Tri Spark unit only had a white/black and a black wire (along with the red wire of course), I initially wired it white/black to white/black and yellow/black to black but it didn't work, no LED or spark. I switched it to yellow/black (from the battery) into white/black (on the Tri Spark) and white/black (from the coil) to black (on the Tri Spark) and both the spark plugs and LED immediately began to work.

I'm at a bit of an impasse now, I'm not sure what to do next to troubleshoot it. I have a spark, fuel, air and compression so I'm beginning to suspect that my timing must be off. I did manage to get an almighty backfire out of the engine by accident while I was manually moving the rear wheel to check the timing, apart from giving me a heart attack there was no other action.

I wanted to ask a couple of questions if anyone has time to answer them:

- What position should the pistons be in the cylinder when the Tri Spark LED comes on? I'm assuming at or near TDC.
- How do I know which marking on the timing rotor is for TDC and which is for BDC?
- How can I double check timing to make sure the timing rotor is correct?
- What timing position do you use with your Tri Spark?
- Do you have any ideas for other troubleshooting tips I can try?

Sorry for the wall of text and thanks for any replies!

Sounds to me that you might be 180 degrees out, is this possible, have you tried altering it.
I would have thought that you have the wiring ok, unless you have the wrong spark going to the wrong side? :?

Branch said:

With the Tri Spark unit, in the instructions it looks like I am supposed to install the white/black wire from the coil to the white/black wire on the Tri Spark, and the yellow/back wire to the yellow/black wire that leads to the positive battery terminal.

Click to expand...

The Tri-Spark diagram for positive earth clearly shows black/yellow (not "yellow/black") connects to negative (normally a white/yellow) from the ignition (and kill) switch, not the battery positive terminal.

Branch said:

My Tri Spark unit only had a white/black and a black wire (along with the red wire of course), I initially wired it white/black to white/black and yellow/black to black but it didn't work, no LED or spark. I switched it to yellow/black (from the battery) into white/black (on the Tri Spark) and white/black (from the coil) to black (on the Tri Spark) and both the spark plugs and LED immediately began to work.

Click to expand...

If they've changed the wire colours then I don't know, but to me, logically, the black ought to be the negative wire, however, can you explain what you mean by: "yellow/black (from the battery)"? If yellow/black (black/yellow) is connected to battery positive as you stated, then it isn't right.

Branch said:

- What position should the pistons be in the cylinder when the Tri Spark LED comes on? I'm assuming at or near TDC.

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It should be 28 degrees BTDC. (Ins. Step 3). http://www.trispark.com.au/images/Class ... 202013.pdf

Branch said:

- How do I know which marking on the timing rotor is for TDC and which is for BDC?

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If you mean the Tri-Spark rotor, then there are no markings on the rotor as far as I'm aware, only the two magnets 180 degrees apart, so there's no 'TDC' or 'BDC' position for the Tri-Spark rotor position, either way around is correct.

Branch said:

- How can I double check timing to make sure the timing rotor is correct?

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I can only suggest you re-read the instructions again for counter-clockwise rotation "B".

Branch said:

What timing position do you use with your Tri Spark?

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28 degrees BTDC for a Tri-Spark (although the instructions mention "29" degrees).

peter12 said:

I would have thought that you have the wiring ok, unless you have the wrong spark going to the wrong side?

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Not possible, as the Classic Twin is a wasted-spark system, so both sides always spark together.