Chinese 250 quad wiring problems.
 

Hi, I have got a 'Zongshen' 250cc water-cooled engine with a 'reverse and 4 forwar'd gearbox, I got this as a 'Kit' with everything including cooler kit, wiring, etc.However, when it arrived the wiring only consisted of the bare loom and no switches, wiring diagram, etc. This has 3 yelow wires going to the rectifier, and a blue/white and green/white going to the CDI. The blue/white also branches off 3 wires at the front of the loom, Can anyone help with where these wires go or what they are for ?? I've opened the loom and have traced all the other wires, but these ones I can't find on any wiring diagrams I have been able to find. Any help is well appreciated.

So do you have a total of 5 wires coming out of the stator? Three yellows, a blue/white, and green/white?

Three yellow wires to the regulator is standard fare for a three phase battery charging scheme. Blue/White (CDI timing trigger) and Green/White (trigger return) are standard colors for the CDI trigger function. If your CDI is DC powered then that's all the wires needed out of the stator. If your CDI is AC powered then we need another wire (usually black/red) coming out the stator as well

Just to verify that the blue/white and green white go to the timing pickup coil inside the stator, take a meter and set it to measure resistance on the 2K ohm scale (2000 ohms). Measure the resistance between the blue/white and green/white wires into the engine. What do you measure?

You say that this blue/white wire from the stator branches off to other wires. This part has me a little confused - normally the ignition timing trigger signal does branch off to other things. It is conceivably possible to kill the spark to an engine by shorting this wire to ground, but it isn't commonly done. Hence my wonder...

First let's verify that the blue/white and green white wires *are* your CDI trigger signal by the above test.

And so I can be thinking ahead, how many wires connect to your cdi, and what are the colors?

How much effort are you going to put into this? How much do you know about this quad's history? Suppose you get all the electrical stuff to work enough to produce spark, and it still doesn't start? Are you up to going through the carburetor, measuring engine compression, rebuilding the engine if necessary, etc? This quad looks to me to already be someone else's basket case ;).

I'm just trying to get you prepared about the possible outcomes here... :).

250 wiring
 

Hi, the blue/white and green/white go from stator back to CDI, and 3 yellow to the rectifier. The green/white goes to the CDI direct. The blue/white goes to CDI and 3 other places. These 5 are the only ones going to stator, all other wires come out of the gearbox.

CDI has black/yellow (coil), blue/white and green/white (stator), and green (earth), all on a 4 pin plug, then out of the 2 pin plug there is only power. There is no kill switch wire.

Would it be possible for the branch off to go to tacho and kill switch to ground ?? The closest wiring I can find to mine where one of the stator wires does branch off (apart from the ground), it goes to a kill switch, a rev limiter and the main dash cluster. but other aspects of that diagram are different, so I'm not sure.

Thanks.

From your wire colors it appears that your quad is using the standard colors for each function. That helps a lot. It also appears that your CDI is DC powered.

It is perfectly legit to kill spark by grounding the blue/white trigger wire with a switch. I've never seen it done that way - normally (for quads that don't use the CDI kill switch input) I see a switch in series with the trigger wire. In other words the switched is turned on to connect the trigger signal to the CDI (allowing spark), and switched off to disconnect the signal (killing spark). But again grounding the trigger signal to kill spark will work just fine.

I didn't think about tachometers. It is possible that a tachometer could work off the trigger signal. Same with a rev limiter. You could always get the quad ignition circuitry working with these extra connections disconnected. To kill the engine unplug the trigger wire at the stator (it is all low voltage there since your CDI is DC powered and there is no high voltage AC power winding in the stator). Then add the kill switch and other stuff one at a time.

The thing about chinese wiring diagrams is they rarely match an unknown quad exactly. But there are only a few ways to wire up an ignition system, and a few ways for the battery charging system, and a few ways for a starter interlock, etc. In combination, that makes for a lot of wiring possibilities. But if you take just it one system at a time (say the ignition system) you can usually find a diagram that matches fairly closely. But other systems probably won't match, and you'll have to use a different wiring diagram for that part.

ok, thanks. Sounds like the type of wiring set-up off an old (30 year +)2 stroke or similar. After 3 months I can finally finish the wiring without wondering if I'm going to fry the electrics.

Thanks very much for your help.

I reread what I wrote and realized I left something very important out:

Make sure your hacked wiring has a fuse feeding everything off the positive battery terminal other than the heavy gauge starter wiring through the starter solenoid. The fuse value should be 10 amps.

The reason for this is that if something is wired wrong it will simply blow the fuse instead of starting a fire. Plus, often times a ten amp current surge through a miswired part (regulator, CDI, or whatever) won't blow up the part. There is no guarantee of that, but often it is true. But 100 amps (which your battery can easily provide) will always do major damage - often will full sound, a light show, and shrapnel. ;)

No worries, Thanks. Got the new stator, a new basic wiring loom (just enough to run), and built the rest of the loom and put it all in, fuse box included, and all a goer. headlights, spotlights, dash instruments, thermo fans, etc. all run perfect. had really thin wires from battery + to solonoid and battery earth to motor which lit up a bit while winding over, but put thicker better quality leads in and all good. Now if I can only get the motor to run smooth, but I think that's timing ......

Thanks very much for your help. GREATLY appreciated.

Wiring
 

No mine has black and red blue and white green and white red yellow