CDI help needed

[kcr100]

hi all ash here from the uk recently got a 2000 kymco cobra racer 100cc scooter

from what i can see the wiring is designed for it to run
only with the battery connected, disconnecting the battery while it runs
confirms this, i don't think its faulty from what i can see(?) my question is
how do i run it without a battery, i think i have a general idea how it works

here goes..

from the engine/stator there's 3 wires, yellow (charge battery?), white (lights?), and blue/white (trigger?)
the cdi is a 6 pin cdi which takes charge from the battery to fire(?)
so is there some way of me taking charge from the yellow/white wires or from the regulator output (red wire?)
when kick starting the scooter? or would it be too little voltage?

cheers

edit: got it working now, just got to work out why the ignition switch dont cut it out and why the indicator relay buzzes, guess its got ac running through it from the engine rather than dc from the battery, will update when ive fixed it

edit2: if your wondering why i dont just fit a battery, the one that came with the scooter is dead, and if i dont have to run one it saves me a few £ and sheds a little weight, and losing the electric starter doesnt bother me

[blue]

I have always been told never run your scoot with out a battery.its there for a reason.the stater just keeps all the lights working and the battery charged up. you might over heat something with out the battery.

[kcr100]

Ok,

managed to revive the dead battery by hitting it with 40v for 10 mins so going to use that for now
ill still have to battery-less it when i come to rat the scooter, ill probably just pull out the old
wiring harness and make my own, and re-wire/re-coil the stator for my needs

anyone got a wiring schematic for the cobra racer 100 or similar scooter?

[axy]

I had Kymco Cobra Cross 50 2000 a decade ago. I still see it on the road occasionally in my hometown.

Just so it does not go unnoticed, running anything without a battery is a VERY BAD idea. Shaving off a kilo or two is pointless and will not gain significant performance, unless you are into rat-scoot dirt racing or things like that.

Among other things, battery is used in an electric circuit as a device that polishes "spikes" in electric current. If you tried to run any modern car that has a lot of electronic devices inside without a battery, you could do a great deal of damage doing so. For example, you could destroy systems like ABS, dynamic stability, remote locking and even trigger airbags!

If you had a new scoot that has injection, you could easily fry a number of things.

Older scoot like yours at least has a CDI that could get burnt.

So, I would not recommend removing a battery from the circuit to anybody that uses scoot on a daily basis as a normal vehicle.

[kcr100]

Ok,

im not after any performance im old school
batteries are an annoyance when you have a lot of scooters
most of my scooters are vespa classics/custom builds which dont come with batteries
and use CDI ignition and ive been running most of them for over 20 years

if someone could answer my question please,
does anyone actually know if this is possible with this scooter on its original wiring harness?
i could confirm it pretty quickly with a wiring diagram but i cant find one anywhere

[blue]

the only IM thinking is you have to by pass the cdi box some how but with out the cdi box you may not have the revalator working like it should .im out not sure it can be done but your welcome to prove me wrong.

[sidthesloth]

G'day kcr, I am not familiar with your model but, if you can get am a/c fired cdi unit you should be able to do it if you are willing to do a bit of rewiring for it. Removing your battery may mean your indicators and brake light may not work, though I am not sure about this. If they do work, they may draw excess power from the other circuits, headlight, tail light and ignition. But to answer your question, yes you should be able to.

[Rianna]

Welcome to the forum, kcr and good luck!

Hi, sid, long time no see.

[Agent Bob]

You say you may have AC running through the engine with the battery removed, but it will run. Try placing a large electrolytic capacitor where the battery once was, observing polarity and of a voltage rating of greater than maybe 20 volts. I didn't say 12 volts since the peak of the wave should be greater than 12 volts. An electrolytic capacitor could blow if polarity is wrong or voltage rating is too low, so be cautious. The capacitor should supply the filtering that the battery used to do and that MAY do it. (Or I'm full of it LOL!) Good luck.

[sidthesloth]

Point taken.

[Hoolander2]

Hey, Sid, it's good to see you around!  How's that ZX doing?  We're still missing Zombie and Wordslinger. 

[kcr100]

hi thanks for replys,

i have some old CDI's lying around anyone know what the resistance between what pins can tell you if its a good CDI or not?

[sidthesloth]

G'day kcr100, I don't know what the readings are, when I bought a zxr cdi for my zx, I bought a digital multi meter to check which pins were which, but the meter did not have the righ range, I ended up using an analogue meter and though I didn't get the right figures I could work out where each one went. If you get a cdi and can get the diagram for the model bike it came from you should be able to work it out quite easily.

G'day Hoolander, hope you are keeping well. The work I did on my zx was good, but, I think I am still skirting around the issue of the exhaust, I think that is not flowing as well as I need. In the new year I will try o make some money available to buy some new bits for it, starting with the exhaust, after all, if you want to put more air fuel in, you must be able to take it out. Take care Hoolander.

[sidthesloth]

I don't know if this will help you, but here is a diagramn for a zx 50 ignition system.