SJ50QT CDI - 3 Wire?

[zebra49]

I have a suzuki SJ50 and am trying to fit an aftermarket CDI.

The CDI in the bike is a 5 wire CDI but the two black wires are joined together from factory so only has 3 wires left.

I've done my best to figure out what these are, it seems one goes to the coil, one to earth and one to the ignition switch.

How do I go about hooking up an aftermarket CDI?

[awayatc]

Doesnt the after market cdi have instructions....?

from what I can remember when I f*cked about with old bikes is that 1 wire is earth....
one wire shortens the live one from stator (Killswitch)
1 live one from stator.....crank motor and see which one has electricity...
1 wire from pick up
1 wire going to coil

sounds to me your 2 black wires are the earth and one to shorten circuit...ie killswitch wire.
maybe try that first....?
maybe your cdi is ok.....just your wiring isnt.

You can actualy try to revive old cdis if that turns out to be the problem...

[awayatc]

Just see you are in whanganui......

May even blast over that way ....?

any how , if you have problems, send me a pm, or give me your number and I can talk you through it......should be piece of cake.

[zebra49]

Cheers for the reply, the current CDI works fine but has a rev limiter so have one of the generic blue Chinese things to fit to it.

I have a wiring diagram for it and it shows three wires, one to earth, one to the ignition switch and one to the coil. I'm guessing it gets the AC from the ignition switch somehow before the recitifer but I have no idea how it gets the signal.

I have no idea what the other "two" wires coming out of the CDI are, it looks like a black wire just looped out of the case, tempted to cut it and see what happens, worst case scenario I can just solder it back together.

Be great to hear from someone who has put an aftermarket CDI into a SJ50QT before.

[zebra49]

This is the wiring diagram

[awayatc]

Sorry buddy......checked up on it a bit, but cdi will need 5 wires.
Not sure what you got, but if it only has 3 wires it doesnt look right.
on trade me a guy in new plymouth is selling race cdi units for your sj50qt for $30.they have 5 wires......
Sorry cant link from bloody android. Have a look on TM
The

[Bobway]

Alternatively you could just wire it to a pgo and see if that works, lol.

[zebra49]

It's definitely only a 3 wire, I put a scope on and had a play and compared the two CDI, the three wires are signal, coil, ac. Kill switch is wired through the other coil wire, no idea how it's earthed at all.

The two other wires connected together are both 0.7v AC at different frequency. One is like 70hz at idle and the other 110hz at idle. Absolutely No idea what they do, cut them and it didn't affect the rev limit.

It seems like the problem with the new CDI is the trigger timing is different between the two. Doesen't work regardless but might try the ones off trade me at some time. Fitted it to the PGO previous post today so it didn't go to waste.

[kezzab]

Sorry buddy......checked up on it a bit, but cdi will need 5 wires.
Not sure what you got, but if it only has 3 wires it doesnt look right.
on trade me a guy in new plymouth is selling race cdi units for your sj50qt for $30.they have 5 wires......
Sorry cant link from bloody android. Have a look on TM
The

The CDI's on TM from New Plymouth don't seem to work. I know a few scooter experts who tried and they couldn't get them to work. If anyone knows of one that works on a SJ50QT can you let me know. I am trying to track down someone that has done it successfully.