Tomos A3 CDI conversion (3 wire stator to 2 wire CID)

spencerrrrr r /

In an effort to keep my alukit cool at WOT I decided to swap out my stock 3-wire ignition system for this A55 CID + parmakit, yay ignition curve.

Unfortunately, I no longer have brake lights. I believe the brake lights were powered off the blue wire on my old 3-wire stator.

What are my options as far as powering my brake lights? If I run them off my lighting coil then my head light dims dramatically when I engage the breaks (this happened when I swapped a 3-wire stator for a 2-wire stator on an older a3). Can I run the brake light off my ignition coil? Would that necessitate an additional voltage regulator between the ignition coil, the brake light and the CID box? I've looked through the A55 wiring diagrams but can't seem to find the secret...

Any input is appreciated, thanks in advance

Re: Tomos A3 CDI conversion (3 wire stator to 2 wire CID)

spencerrrrr r /

ugh, 'CDI'

Re: Tomos A3 CDI conversion (3 wire stator to 2 wire CID)

♣Slew Foot♣ /

The blue wire was actually your negative ground for the stator he went through the tail light resistor so this is what you do is this simple you take your yellow wire that comes out of the stator that goes to your voltage regulator the black wire goes to the CDI trigger the negative ground for the CDI trigger the Box gets put right to the frame or a big negative Ground Terminal then you realize you have no kill switch so you take the voltage regulator out the yellow and you split it you're right through all the lighting now at least your brake lights are always on and your headlight but you don't have a kill switch I usually use a choke or I'll freaking set the idle so low that it will kill it when I let off the throttle you could also turn off the gas and Wait Awhile which is pretty cool cuz then you don't have to worry about leaving puddles of gasoline everywhere

Re: Tomos A3 CDI conversion (3 wire stator to 2 wire CID)

spencerrrrr r /

So I use the ground coming out of the CDI box as the blue wire in the 3-wire stator? I don’t mind not having a kill switch, I usually just put my hand over the carb to stop the engine. What I’m really going for is bright, functional running and brake lights.

Re: Tomos A3 CDI conversion (3 wire stator to 2 wire CID)

Just wire the brake lights into the headlight circuit.

Re: Tomos A3 CDI conversion (3 wire stator to 2 wire CID)

spencerrrrr r /

That’s what I’ve done in the past, along with swapping out the brake switches to for the kind that are ‘closed in the paused position’

It works but I hate how dim the headlight bulb gets when I’m on the brakes.

I mean there are plenty of two wire stator bikes out there with fully functioning brake and running lights.... there has to be a way

Re: Tomos A3 CDI conversion (3 wire stator to 2 wire CID)

♣Slew Foot♣ /

If you ever had an English motorcycle or a sax or any 2-stroke you'd realize that if you just have a Magneto it's going to get dim you could wire a battery box in and then it wouldn't dim otherwise you'd have to downgrade all your bulbs 2 LEDs and then you have too much voltage in you be blowing stuff out so by my advice is to just live with it

Re: Tomos A3 CDI conversion (3 wire stator to 2 wire CID)

spencerrrrr r /

Well I buttoned up the wiring today and took it for a spin. Turns out the big old lighting coil that came with the early-style, 2-wire A55 CDI is beefy enough to run the headlight /tail light and the brake light off the same circuit. No dimming of the headlight when the brakes are engaged! I suppose the old 6V A3 lighting coils couldn't handle the demand.

I had to remove the woodruf key/pin to set the flywheel in the right position. Timings set to 1.8mm BTDC a hair above idle and retards down to 0.8mm BTDC when reved out. Temps are way down, even at WOT and at distance Im maxing out around 300F. I might try advancing it a bit.

Hope this helps anyone upgrading their old A3 to something a bit more fast, reliable and cooooool.

Re: Tomos A3 CDI conversion (3 wire stator to 2 wire CID)

♣Slew Foot♣ /

Yeah that timing probably needs to be Advanced a little bit it's probably so retarded that if you check your pipe temp it's probably turning red hot If you let it go you're going to hit a bump and your pipe can bend write off

Re: Tomos A3 CDI conversion (3 wire stator to 2 wire CID)

spencerrrrr r /

Oh interesting, I never considered EGT and pipe longevity... too concerned with head temps

Re: Tomos A3 CDI conversion (3 wire stator to 2 wire CID)

♣Slew Foot♣ /

Head tabs generally can go up to about 400 but the pipe the exhaust that gets temperatures of 800 is good somebody else should ring in cuz I never really had a freaking temp gauge

Re: Tomos A3 CDI conversion (3 wire stator to 2 wire CID)

I just installed the a55 CDI from Treats in my a3. Can you be more specific as to what wires you ran where to get the brake light working again? Thanks for your help.

Re: Tomos A3 CDI conversion (3 wire stator to 2 wire CID)

spencerrrrr r /

Just run your rear running light, headlight and your brake lights off your light coil (and voltage regulator). You’ll need to swap your brake light switches to the kind that are ‘off in the paused position’ so that when you engage the brake lever the circuit closes and juice runs to your brake light bulb.

The lighting coil on the tomos CDI is butch enough to light the brake lights without dimming the head light, which is not the case with my moby CDI that happens to be wired up identically.

« Go to Topic — end of thread

Want to post in this forum? We'd love to have you join the discussion, but first:

Login or Create Account