Jubilee, Navigator Electrics update, including Electra, 12V and
electronic ignition.
The Jubilee and the Navigator have an identical electrical system from Wipac so the
following conversion from 6V to 12V and electronic ignition covers both bikes.
Electra owners need to take note as well.
Due to the ravages of owners/time on the wiring it is likely and advisable that a
complete rewire is also planned at this conversion. Upgrading a new 6V loom will
leave you with several areas of rewiring/connecting, including the ‘Resistor wire’ in
the old loom, which is not needed. In fact some new remanufactured looms do not
have this wire or have an ‘unsafe’ resistance wire in the loom. Either way a 15W 3
ohm resistor is what you need if you must continue with 6V. (Get in touch if you
want a resistor or have any doubts). So a new rewire is recommended but initially
you will need to decide on switches.
Switches/sockets The original switches (they are identical, just have different knobs)
may be usable perhaps even with a little servicing if you can get some switch cleaner
(or WD40) inside and give the switch a workout. Be careful if trying to take the
switch apart-they tend to self destruct ...balls..and springs! etc. The sockets are not
available as a separate item. You might be able to use the old ones with some
cleaning up but a recommended sort out is to solder short lengths of correct coloured
wire to each flat switch blade (it’s brass, easy) then cover the joint with heat shrink.
Then traditional bullets on the wires to connect to the new wiring loom. It is possible
to find a Luca connector that almost fits, but there is not a lot of room for an
insulator.
Alternator. The Wipac alternator parts fare very well for their age and the stator can
be replaced with a Lucas one if you must. BUT as the crank is 1-inch diameter there
isn’t any rotors! Re-magnetising is possible. Stator checking-first a good inspection,
are any coils loose? Are any wires bare and liable to short to earth? Then check that
the readings across the coils 1.5 to 3 ohms while there must NOT be any connection
between any alternator wire and the metal pole pieces. To get to 12V-all of the
alternator wiring that goes to the lights switch is redundant and is removed.
(Disconnected and made safe if you must modify an old loom) The alternator is
reconnected as a two-wire unit. ORANGE and Light GREEN connect together.
WHITE is the second wire.
Rectifier. The original was a large square thingy in pale green/brown or even a shiny
green with rubber edges-THROW them away! The black ‘circular Lucas unit in good
order can be retained OR fit a modern encapsulated unit, that is if you are going to fit
a Zener diode for regulation. If not, then a modern Regulator/Rectifier is
recommended.
Capacitor (2MC type). It is recommended that you fit a capacitor, to assist in flat
battery/emergency start situations, as the emergency start facility is lost when on 12V.
Battery. 5 AHr is the minimum I recommend for British motorcycles, larger if you
can get it in. Do not use batteries from the Alarm world! These usually have very
square corners, are sealed and have spade terminals. They will overcharge and dry
out in due course. Only use a battery that is for ‘automotive use’.
Bulbs. Headlamp-bearing in mind the size of it then fitting a new 7” reflector unit is
unlikely. Fitting 12V halogen lamps to an old style reflector is also liable to give an
average result. The best result is use a reflector unit specifically made for Halogen
lamps ie the H4. Dare I say the right size reflector unit can be found from Japan.
Fuse. You must fit one, 12V is more powerful than the old 6V. 25A or thereabouts.
Horn. New at 12V.
Ignition. If you do all of the above and do NOT change to electronic then you are
being ‘silly’. The original advance retard will be well worn, the points will be very
tired, often new ones are of poor manufacture, getting condensers to fit in with the
points is virtually impossible unless you modify some thing from the 60s car world-
don’t do it! You will also have to buy 2 new ignition coils, which is half the cost of
the electronic ignition!
Fitting electronic will reduce vibration, extend engine life, improve starting and save
fiddling and breakdown time. I rest my case. Setting ignition timing is 10 times easier
and far more accurate as you do it dynamically with a strobe. The initial engine
timing with electronic will take as long doing one cylinder with points and will take a
quarter of the time, thereafter!
Ignition coils. Retain the two Wipac 6V ignition coils as they suit the Boyer-
Bransden or Pazon ignition perfectly. As well as fitting very neatly under the tank
they are long term ultra reliable. (Also saves the cost of two new coils).
Fitting Boyer Bransden ignition. There are a couple points (sorry about the pun) to
note. When you try to fit the pick-up stator plate you might find it sits a little to far
into the ignition rotor and so touches it. The best way to clear this is to have the taper
on the rotor, that fits into the cam, machined a couple mm further towards the
magnets. Retain the taper of course. This allows the pick-up rotor to be positioned
further into the engine giving the stator plate clearance.
Ignition timing. You will need some timing marks (fixed and rotating) on the
alternator. You need a pointer fitted under a stator stud/nut. (A O has a specific
design/part) And a line scribed on the rotor to coincide at the fully advanced ignition
point. These need to be used when strobing the ignition in line with the instructions
that come with the ignition kit.
