I bought a Ducar 150cc quad off a guy cheap cause he was having trouble getting the charging system to work. He replaced the battery and regulator and no luck. I went in and replaced the stator,(only thing left) and still no charging system. I've checked all the wiring and connections and all is good. The only odd thing I noticed is the clearance between the stator and the flywheel seems to be excessive at about 3/16". I'm thinking someone possibly built one bike with 2 and used the wrong flywheel. Does anyone have any ideas on this?

 

Make sure the number of magnets imbedded in the flywheel equals the number of pole pieces in the stator. My 150cc quad has an 8 pole stator - i.e. there are eight coils on the stator, 7 of them are dedicated to charging the battery and one (looks a liitle different) is for providing power to the ignition system. I have eight magnets in the flywheel. Six pole stators (and flywheels) are also common. The flywheel and stator poles/magnets must match or the charging system won't work.

You can do some voltmeter measurements to isolate the problem to the stator or regulator or battery. Wiring problems can also be isolated. You mentioned that you changed the stator because it was the only thing left. Not quite true - there are still the open and short type wiring problems (very common), and also mis-wiring problems (others have flailed at this and given up - what did they mess up during all their flailing?).

Do you have a wiring diagram? Do you have a voltmeter?

If you don't have a wiring diagram then copy these links into your browser for a wiring diagram of my 150cc quad. Yours is probably very similar:

i397.photobucket.com/albums/pp60/LynnEdwards_photo/QuadSchematic1.jpg

i397.photobucket.com/albums/pp60/LynnEdwards_photo/QuadSchematic2.jpg

Normally there would be a "http:\\" in front of each of those links but for some reason if I leave them there they blow up when I preview my message. You don't need them anyway - just copy them as is and it should work.

Let me know if we need to do some voltage measurements.

 

Hey Lynn,

I counted the imbedded magnets in the flywheel and there are 8. The stator on this bike has 6 poles. If you are sure about what you say,(numbers must match number of poles on stator) then I believe we have found the fault. The only issue now would be does it have the wrong flywheel or stator installed? Good question as the folks that sell parts for these bikes do not go by application books, they basically look at the old part and match it up to the existing one. Thanks four assistance.

m_mowat

 

You have absolutely found the problem. The magnets and pole pieces on the stator must match. Here's why:

You have two winding sets inside the stator (and a third timing trigger winding outside the flywheel). The ignition power winding is a single coil wound on one pole. This winding has lots of turns of fine gauge wire which makes high voltage at a low output current. The other five poles have coils that are all wired in series, essentially making one big coil used to charge the battery through the rectifier/regulator. These coils have less turns of a heavier gauge wire so they produce a much lower voltage but at a much higher current. In order for the coils to work together in series the north and south poles of all the magnets have to pass all five coils at the same time so that the produced voltages add up together. If the magnets aren't all aligned with the pole pieces then the individual coil voltages won't add up - in fact some of the coils will be so out of phase they will be producing backward voltages subtracting from the total output. It is kind of like trying to run a flashlight with some of the batteries in backwards. It won't work.

The ignition power coil is a single winding, so it will still work with eight magnets flying by instead of six. It will just be running with 33% more voltage than usual.

Eight pole stators put out a little more power (55 watts IIRC) than six pole stators. On my quad (with an eight pole stator) if I run the headlights on high beam the charging system barely keeps up with charging the battery at running speeds. At idle the headlights are actually discharging the battery slightly. Since a flywheel and the stator are roughly the same price I would buy the eight pole stator to match the flywheel.

Lynn Edwards