Britbike forum Forums British motorcycles in general British modified/specials NEGATIVE GROUND BOYER INSTALL

Good morning guys!
I am just starting the wiring phase of my 1970 Triumph TR6R bobber project.

I purchased a KIT00284 / 281 Boyer unit that comes with a micro-power coil. This is a very compact set up and will fit nicely in to my custom battery/switch box.

As I want to run LED headlight and taillight bulbs, I want to run my wiring as a negative ground system. The Boyer instructions have a wiring diagram for negative ground installations, so I believe this is not an issue.

I have ordered a Podtronics regulator and will also wire this unit in with negative ground

Does anyone have any advice or challenge to this option?

Thank you
John

You'll need a proper kill switch. A grounding button won't work.

Looks like you have the wrong Boyer; it's says "Norton" on it.

Should be a Triumph unit. I believe your advance will be wrong, as they rotate in opposite directions. I don't believe they'll work by simply swapping the trigger wires, but I have been known to be wrong before...

I just installed a Boyer Micro on a Triumph, it can be set up CW or CCW...But I believe the Norton unit has less advance built in as Paul says

Paul
I purchased the unit from a reputable British parts supplier. I too questioned the Norton logo on the instructions and was told that the unit is exactly the same with the exceptions of different wire lengths, which is not a problem. On the instruction sheet, it states for Norton and Triumph.

i researched this on the Boyer site and the part number I received is KIT00284 and the actual Triumph unit is part number KIT00281, but the components are the same.

However, as this unit is very expensive, I am going to contact the supplier again to question regarding the advance timing differences between the two.
Regards
John

Make a proper harness with live and return wires, don't ever rely on the frame

some find the difference between negitive and positive ground confusing ,
but if you look at the 2 Boyer wiring diagrams

...the Boyer box and components are wired the same
for both positive and negative wiring
... what changes is ... the switch side location

only the ignition switch is moved ... and the fuse ... (if you prefer the fuse on the switch side )

the switch for plus ground is on the negitive side .
the switch for negitive ground is on the positive side .
All the rest of the Boyer component stay wired the same .

To avoid wire color confusion , negitive ground should use a custom harness
or one based off a 79 or later T140

Thank you everyone for your input, i am so grateful that British bike enthusiasts take the time to share their knowledge!

I contacted Boyer Bransden directly with my questions and below is the answer I received from them:

Yes, the pictured parts in the Norton Commando ignition kit (KIT00284) can be fitted and used on a Triumph twin.
The Triumph KIT00281 instructions (attached) are needed, the installation on the Triumph is statically set at and then strobed to 38 DBTDC (more advanced than the Norton setting).
The KIT00281 'Micro-Power' instructions for the Triumph also give a Negative ground wiring diagram for later Triumph models, these can also be used with the 'Micro-Power' Norton kit.

Regards,
Boyer Bransden.

At that point, you lose me because I've never tried it, so I can't say if the advance shortfall is detrimental to X, Y, or Z.

...plus, I'm getting ready to leave to Maui and I'm not going to spend time researching it!

y'all have fun...

Hi John,
+1.

Except do not connect the Box White wire to "NEGATIVE FRAME EARTH". Connect the White wire either to battery -ve directly or at least to the supply 'bus' wire running the length of the bike. Put a low-Amp (5A?) fuse in either the White wire or the Red wire between coil and ignition or kill switches

From your post #852275:-
Nothing to with "ground", you should connect the Pod exactly the same.

Hth.

Regards,

red-wire to the negitive post ... and the black-wire to the positive post .
Hopefully this is an editorial mistake and not the plan
It's your bike and your battery ,
but I strongly suggest you re-think the plan !

Ha! Good spot. Time for bed, I think ...

Instead of the POD, have you considered the Boyer powerbox? You then have the option of going batteryless. You can even get a box with "lighting delay" so the power to auxillary circuits (lights, horn, or what ever you want) won't come on until the engine is running.

Thank you all for your advice. I apologize for some of my inconsistent remarks on where i was running red and black wires.

I selected the Micro-Power Boyer kit with the mini dual output coil as I am installing the complete set up inside my custom battery box under the seat.

My plan is to run the following:
white wire to the the ground post in my box, which is connected to the frame with a clean, paint free, connection.
black wire to the negative spade connector on the coil.
red wire with a dual spade connector to the positive spade on the coil, with a second connection to the ignition post on my three position ignition switch. which is powered (fused) from the positive post on the battery.

My battery negative post will be connected to the ground post in my box.

My POD box will be connected:
one yellow to green/black from alternator
one yellow to white/green from alternator
black to negative post on battery
red to positive post on battery.

I hope this clarifies my intentions and look forward to feedback. I also attached a photo of my rough build showing the battery box.
Regards
John

quote: "I selected the Micro-Power Boyer kit with the mini dual output coil as I am installing the complete set up inside my custom battery box under the seat. "

Both the reglator/rectifier AND Boyer box must have cool air flowing over them. Both generate heat as they do their respective jobs. As the Boyer box heats up it lowers it ability to handle current. The 5 amp continous ratin drops significantly as it heats up. The switcing diodes in the regulator also generate heat. Their longevity decreases with with heat.

Of course you can do this, but expect one, or both, to fail over time. The regulator not being able to hold the voltage at under 14.4 volts, thus damaging the battery or the Boyer to operate at all. Their is a cost for form over function.

John
Good points. The first photo I attached is misleading, it was taken early on in my build.

I have since replaced the five wire box that came with the bike (in first photo) to a new, four wire Podronics regulator.

I plan on mounting this finned regulator under the batter box to allow lots of air flow. I have a mini battery which allows ample room inside the battery box for the Boyer box to receive lots of air.

Thank you for your input.
Regards
John

Lots of air is essential especially if you ride with LED's or the lights switched off. Mine's under the seat (Commando) mounted on the rear mudguard out of the way of road grit and the wet.

You can use a grounding kill switch, but ONLY if it is connected to one of the leads from the pickup, not to the black box.

As to my reply to your reply, your signature says it all. Apparently I have become wiser today.

Earthing one trigger wire to the frame certainly works ok on the kill switch on my Wassell/Vape ignition. I expect the trigger system is similar to this Boyer.