These numbers don't add up either.

Something is fundamentally wrong here. I don't know what yet. Give me a day to think about it. I'll reread to the entire thread to try and find something I overlooked...

 

I've thought about this over the last two days. There are many puzzling things here, but the one that stands out the most is when you measure different AC voltages between the yellow and white wires at the regulator connector when the meter leads are reversed (regulator disconnected, and at a constant engine speed). That just cannot be if we're looking at just the unloaded stator voltages since they must be entirely AC. But I'm wondering if something else is wired onto the stator output - something that loads the stator differently when the stator voltage is swinging positive compared to when it is swinging negative. That would generate a DC voltage on top of the AC voltage. That could cause some meters to read a difference if the leads are reversed.

Down on the stator where the stator wires come out of the engine side cover, find the wires from the stator that connect to the yellow, white, and green wires in the main wiring harness. These are the other end of the wires we were measuring before at the regulator. The short wires emerging from the stator may or may not match the wiring harness colors. Use the yellow, white, green wiring harness colors as your guide.

Unplug the stator wires (at the stator) from the main harness. Now measure the AC voltage between the stator wires that normally are connected to the yellow, white, and green wires just as you did before. Do this at idle with the engine running at normal idle speed. What do you measure? Do you see a difference in the readings when the meter leads are reversed?

By focusing right down to the stator, and disconnecting it from anything else that might be connected to it through the wiring harness we hopefully will get voltages that add up - i.e:

1) voltage from yellow to green, plus...
2) voltage from yellow to white, equals...
3) voltage from white to green.

 

Sorry i have been busy with other things. I have been looking for another stator as i think that it cold be broken. This is on ebay and all dimensions are the same and looks identical.
Pit Bike 6 Pole MAGNETO STATOR GENERATOR 50cc 90cc Scooters & Quads | eBay
Its only £15 so its worth a try. I have removed the stator and found that all the wires were melted together, not sure if all the way through, The green earth was and resting against the body of the stator itself. To be honest it looks like i need a new one.

 

Ok, I have fitted the new stator. Good news and bad i hope. The quad is not loosing voltage from the battery when running, When i turn ignition on the quad isint loosing any volts.
Volts at regulator ;
Y-G= 30v
W-G=36v
W-Y=17.2v

Please tell me these add up. Im confused about when you say "Unplug the stator wires (at the stator) from the main harness."
When do that quad does no run as the wires for the CDI unot are not conected.

 

Those numbers don't add up, and they have been consistant all along in not adding up. This has me baffled. The only way this can happen that I can think of that the yellow wire and white voltages are out of phase. But when looking at pictures I can't see how this can be. I wish I was there. With an oscilloscope and some wiring tracing this would be solved in short order. But I'm baffled at the moment...

Most stator have different connectors for the ignition section and the battery charging section (which are completely independent of one another). You're right, if you disconnect the ignition stuff at the stator the engine can't run. Can you just disconnect just the yellow and white wires (and maybe a green wire will be on the connector too) - leaving the ignition wires still hooked up?

 

I'm having a similar charging issue with a Buyang 90 (loncin engine) that started happening less than a year after purchasing new and dealer is now out of business. I have 5 wires coming from the stator (4 in a plug-blackred,bluewhite,and 2 yellow) and the green ground by itself.The regulator has a 4 wire plug (white,red,yellow,green).When I unplug the regulator, I have no resistance reading on yellow to green or white to green(not running).With the engine running, I get 0.1V on both the white to green and yellow to green and 22.5V on white to yellow. With no resistance readings, I'm assuming that the stator is shot! Anyone have any input/suggestions?

 

I have a charging issue that has me scratching my head. Everything forked great. Then it didn’t. I can’t get more than 12.6-12.8 volts at 1/2 throttle. ( tested at battery). I have tried brand new stator, cdi, and regulator. Same result. Still no charge voltage. Any ideas?

 

I think you would have been better starting a new post. I haven't waded through all this thread, but either you have bought faulty new components or you have a wiring problem. Other possibility is it doesn't have a voltage regulator anyway, some Kids Quads have only a rectifier, and the battery gets whatever voltage the stator puts out. These stators are made deliberately feeble in order to prevent overcharging. If it does have a voltage reg, it needs good positive and negative wires to the regulator, any resistance will result in it not charging at full power, I test these wires using an incandescent test lamp across pos and neg wires at regulator plug, you should get a bright white light, any dimming of the bulb shows full power is not getting from battery to regulator.