Converting the stator to 12 volts using Bajaj coils --- Chopper
You need the Bajaj replacement coils. They are two coils that are wired in series, i.e. you have one coil
with right end grounded and the left end tied into the right end of the other coil and the whole deal has
one single wire coming off it.
The anvils on those coils are a bit bigger than the original rally ones; what this means is that installing
them as the are will squeeze the CDI pickup on the stator plate, so you need to take out the Dremel and
grind down a bit of the cores of both coils around the pickup. This is no big deal.
When you replace the coils and they fit, you'll have a single green wire going to your junction box on top
of the engine. The thing is, you'll have two yellow and two white wires coming in from the harness.
Usually I pick a few of those wires and ground them at the junction box and ground them on the battery
side, and pick the other ones to use as hot wires. It is your choice. In my case, I picked the two yellow
wires.
So you'll have the green wire connected to the two yellow wires, which go over to the battery side. You
take out your battery and replace the 6V DC rectifier with a one-input one-output 12V AC regulator like
from a euro P series. Both the input and output are labeled the same color, and i don't think it matters
which one you pick as input or output.
Anyhoo, I tied the two yellow wires together at both ends just for the hell of it (those old wires can kinda
suck so why not be careful) and tied them both to the input of the regulator. The output of the regulator
was tied to the green and green/white wires from the harness, which go to the headset and brakes
respectively IIRC.
The rest of the battery wiring and fuses and what not can all go in the bin. i kept them around and
grounded them all, just in case i wanted to go back to 6V for some reason.
Replace your bulbs to and horn to 12v and rock out.
One thing to add: it matters what coil goes on which side.
if you hook the whole shebang up and get no voltage out
(you can just check the AC coming out of the green wire
at the stator) take the coils off and reverse them. -Kyle
You need the Bajaj replacement coils. They are two coils that are wired in series, i.e. you have one coil
with right end grounded and the left end tied into the right end of the other coil and the whole deal has
one single wire coming off it.
The anvils on those coils are a bit bigger than the original rally ones; what this means is that installing
them as the are will squeeze the CDI pickup on the stator plate, so you need to take out the Dremel and
grind down a bit of the cores of both coils around the pickup. This is no big deal.
When you replace the coils and they fit, you'll have a single green wire going to your junction box on top
of the engine. The thing is, you'll have two yellow and two white wires coming in from the harness.
Usually I pick a few of those wires and ground them at the junction box and ground them on the battery
side, and pick the other ones to use as hot wires. It is your choice. In my case, I picked the two yellow
wires.
So you'll have the green wire connected to the two yellow wires, which go over to the battery side. You
take out your battery and replace the 6V DC rectifier with a one-input one-output 12V AC regulator like
from a euro P series. Both the input and output are labeled the same color, and i don't think it matters
which one you pick as input or output.
Anyhoo, I tied the two yellow wires together at both ends just for the hell of it (those old wires can kinda
suck so why not be careful) and tied them both to the input of the regulator. The output of the regulator
was tied to the green and green/white wires from the harness, which go to the headset and brakes
respectively IIRC.
The rest of the battery wiring and fuses and what not can all go in the bin. i kept them around and
grounded them all, just in case i wanted to go back to 6V for some reason.
Replace your bulbs to and horn to 12v and rock out.
One thing to add: it matters what coil goes on which side.
if you hook the whole shebang up and get no voltage out
(you can just check the AC coming out of the green wire
at the stator) take the coils off and reverse them. -Kyle
12 volt conversion by simple wiring change. - The Rooster
You ground one of the yellow wires on the battery side and connect the other yellow wire to the old
battery (+) wire and the green wire. There may be some variation to this, but the same (or similar)
conversion works on A LOT of bikes. My wife's Rally 200 ('78) and a clubmates Rally200 ('73) are
wired this way and work GREAT with a universal 12v regulator.
There may be some trial and error, but the end result is good and you don't have to buy anything but
a regulator and you DO NOT HAVE to remove the flywheel or rewire the stator. You could probably
figure out turn signals with an AC flasher and a bit more experimentation.
I cannot take credit for this, it was handed down/taught to me by some friends.
You ground one of the yellow wires on the battery side and connect the other yellow wire to the old
battery (+) wire and the green wire. There may be some variation to this, but the same (or similar)
conversion works on A LOT of bikes. My wife's Rally 200 ('78) and a clubmates Rally200 ('73) are
wired this way and work GREAT with a universal 12v regulator.
There may be some trial and error, but the end result is good and you don't have to buy anything but
a regulator and you DO NOT HAVE to remove the flywheel or rewire the stator. You could probably
figure out turn signals with an AC flasher and a bit more experimentation.
I cannot take credit for this, it was handed down/taught to me by some friends.
