I am at work right now and will be for another 8 hours so I won't be able to do the meter testing till later today but until then I will bring you up to speed on were I am currently at. I got a used 110cc horizontal chineese go cart with 3 forward gears plus reverse. Shortly after I got it the transmission went out of it. I looked for a replacement engine for it and found a new 200cc lifan water cooled engine online for a good price. I got a new radiator with it since my last engine was air cooled. Engine model # is 163ML-2N. Of course the mounting was different on the new engine but I was capable of making the new mounts and that part is already taken care of. I did not get a main wiring harness or cdi or ignition coil with the engine. I have had the flywheel covers off the old and new engines and they are completely different.

OLD ENGINE
Has 2 coils inside the flywheel. One coil has 1 wire (black/red) that powered the old cdi box.
The other coil has 2 wires and went to the rectifier. There was also the trigger with 2 wires.
Blue/White went to the old cdi and green was grounded to a screw inside the flywheel cover.

NEW ENGINE
Has 1 big round "stator" I think it is called, inside the flywheel with 12 individual coils around it.
There are 3 yellow wires from this. And there is the trigger with a blue/white wire and green wire. The 3 yellow wires and the blue/white wire and green wire all exit the flywheel cover (5 wires total).
The owners manual showes a wiring diagram of a typical wiring setup and the cdi box is labled as being a DC type.

Because my old engine was ac and the cdi only had 1 plug, the old wiring harness was no good. So with no plug for a new cdi box I used small insulated (so I know they arnt touching each other) crimp terminals that are sized to fit each pin on the new cdi. I tried a couple of new cdi's and no spark. So either the boxes I got arnt dc or the problem lies somewere else. I have the cdi wired as shown in your last diagram and it matches the diagram in the engine owners manual pretty close. The top left pin of the 4 pin plug goes to blue/white trigger. The top right of the 4 pin plug goes the the positive on the ignition coil. Now here is were the difference is. The bottom 2 pins on the 4 pin plug both go to ground on your pic. I tried that. In the manual the green wire from the trigger is isolated from the other grounds. The other grounds go to the bottom right pin and the trigger green only goes to the bottom left pin. I tried it this way also. I have the spark plug out of the engine and turn the engine over. While holding the spark plug to the engine case to be sure the plug is grounded, I see no spark on the plug.

 

Also I have done nothing with the 3 yellow stator coil wires. As I understand it, they go right to a voltage rectifier and are for charging the battery. They don't need hooked up to see a spark plug spark. I will get to them after I see a spark. I know my old voltage reg is different (no yellow wires on the old engine) and I need to buy a new one anyways. I got the +12V DC from the battery to the power pin on the new cdi and nothing hooked to the kill switch pin. If I left anything out on were I am at with this let me know. I think I need to do some testing on the trigger and the ignition coil to make sure my other components I need to make the spark are doing what they r suppose to.

 

I did some meter testing. I did get .4 - .5 V AC on the blue/white trigger wire and ground with the cdi hooked up. I measured the power terminal and ground and got 12 V DC. I tested the ignition coil positive terminal and ground and didn't get anything on the ac or dc meter settings. I took the ignition coil and wired it to my yahama rino and got spark. I don't know what kind of ignition system is on the rino. Because it sparked on the rino does that mean it will work on the go cart. I don't know if getting a spark on the rino proved the coil would work on the go cart.

 

Without question you need a DC powered CDI.

I've taken a few of the AC powerd CDI's apart and traced out the internal diagrams. The two ground pins you describe above are tied together on the circuit board inside. So on AC powered CDI's those pins are one and the same. It doesn't matter whther you hook the grounds to this pin or that, just as long as they are connected. I don't know for sure if the DC powered CDI's are like that or not. You could measure with an ohmmeter right on the CDI module to see if those two pins are shorted. I suspect they are, but only you can tell for sure [and the big assumption is that you really do have a DC powered CDI which is not established yet].

 

Yes, but if you have a DC powered CDI you need 12 volts to power it. If you have a battery with enough *ummph* to turn the starter then you don't need the battery charging stuff to work to get spark. The CDI can just run off the battery. The CDI draws very little current compared to the starter motor. Just be sure to keep your battery charged up with a charger else it will be ruined if allowed to sit discharged.

Definately. But this is the next problem to solve.

 

The CDI requires power and a trigger. You have good trigger voltage to the CDI. You have good power voltage to the CDI. You have no output from the CDI. I think you have a bad CDI.

Here are some links to eBay CDI's that are advertised as DC powered. I can't vouch at all for their veracity, so do your own research and ask questions before buying:

6 Pin DC CDI GY6 150cc Scooter Moped Go Kart ATV Quad : eBay Motors (item 280453190761 end time Apr-17-10 23:01:38 PDT)

Performance CDI (DC) for GY6 150cc Scooters and ATVs : eBay Motors (item 220563387847 end time Apr-27-10 22:43:16 PDT)

You may not get optimum spark with an ignition coil that isn't matched with the CDI, but the fact that you get spark at all proves it isn't dead.

 

Well I bought another cdi and it was identified as being DC. It is comming from the other side of the country so I won't have it till the end of the week. I will post my results.

 

Well I got my cdi and it worked this time. I now have a running engine. It does need some tunning work. Engine cuts out if accelertating to quickly and also is cuts out on top end. Not sure if this is a carb issue or a trigger timming issue. There is a small amount of slop in the trigger mounting screws. Not sure if the amount of slop is enough to affect spark timming. As far as the carb I see no air mixture screw like I have seen on many japaneese atvs like honda and yahama. I don't remember seeing height adjustment slots on the needle either but I will have to look at that again. The voltage regulator is on order and will get it soon. I got one with 3 yellow wires thinking that is what I need for my dc ignition. My engine is water cooled 200cc lifan engine and I noticed what looks like a temp sender. Resistance went down as engine heated up. I would like to find a guage that is matched to the senders resistance. I mounted my radiator but not sure if I am getting enough flow. After I was done riding for 15 minutes the resistance was approx 74 ohms.

 

Glad you got it running...

The trigger coil should be set close to the flywheel but not touching. Be sure to spin the flywheel around and find the raised bump that does the actual triggering. Set the clearance to 0.025" at the raised bump. The symptom of a coil that is too far out is hard starting, or no starting with a slightly discharged battery - where the starter spins a little slow.

The triggger gap may affect spark timing in a very minor way, but I don't think it cause any of the cutout symptoms you described. I'd suspect carburetor issues instead.

 

Hi Both

Sorry for the silence yet I have injured my arm which stopped my tinkering with the quad.

I have followed Lynn's advice and concluded that the reg/rect that was purchased was faulty and was sent a replacement and all is fine it runs and charges, many many thanks for all the help.

Mustang sorry to hear of your prob I fully appreciate what you are going thro but stick with it. If it would help I can post up some piccies of my stator, cdi, reg/rect etc as I think we have the same engine. Please let me know if this would assist.

Couple of final questions, with the live from the reg/rect to the battery should there be a fuse between the two? If yes what rating ?

Lastly I want to fit a kill switch that will basically isolate the entire battery/engine and to prevent accidental cranking if the kids get to the quad without me. ANy idea what current rating it would need to be as I dont know what current is used to crank the engine.

Many thanks for all the help so far