magneto help please By hooklink (Read 2,469 times)

[hooklink]

hi im trying to sort my sons scooter it is a twist and go hanglong 50cc scooter.The lights and indicators dont work i have traced it to the magneto not putting out any ac voltage.I have got a new one the only problem is it has no green common wire that goes to the voltage regulator every thing else is exactly the same plug size wire colour design etc. Can any let me know if this will be a problem

[ccprof]

Welcome! Have you checked out the tech section? You may find the answer there. I'm not going to offer advice because I have no knowledge of that scoot/engine. I'm sure some of the experts like Dr. JR will get back to you.

Happy Holidays!

[tvnacman]

if the feild wire is dead no out put a/c or dc ,, in short, check the fuse
check the charging system , if you can't find ac then your not charging , a good ground to check for ac is the neg battery termnal . do a few quick checks and let me know what you find then we can go from there.
John

[hooklink]

hi
many thanks for replying.I have check all charging systems light system and there is nothing the only readying i get is from the block plug that goes to the voltage regulator red wire whic comes from the battery when it is unpluged and engine running there is no voltage a/c or d/c from any wire in this block.If i trace the wires back to the first plug from the magneto there is no out put from any of the wires hence why i feel to magneto is bad.i did it this way just incase there was a break in the loom some where.my problem now is the new magneto has no green common wire and im not sure if it will be ok to fit or not.As you probably guessed im not a auto electrican lol
many thank hooklink

[Bashan]

One of the things I have determined from taking my scooter apart and putting it back together countless times is Green=Ground=Green=Ground ad infinitum. The geen wire that came off of my stator worked fine grounded to the frame as long as the rectifier was grounded as well. Now, what I'm confused about is did you have a stator with a ground and then bought one that didn't? If so that could be a problem, if the original stator had a ground wire it just needs to be grounded, it's not necessary to run it to the rectifier as long as you ground it too. Now if the original stator didn't have a ground wire, don't worry, some of them ground at their mount. Rich

[Bashan]

There's some variation with stators especially with the 50ccs it seems. However, the stator has two functions, it's going to supply 50 to 100v AC through a red or red/black wire to the CDI. You can test this wire by setting your multi to AC, put the red in the red off of the stator, ground black to frame and crank the starter. Next, the blue off of the pick up gives about .05v AC to fire the coil. Set your multi accordingly, red into blue, black to ground, crank the starter. That's the ignition part. The other wires energize the lights and charging system in various configurations. The yellow typically gives about 10v AC while cranking, the white about 20v AC. Use the same multi set up, red on the wire, black to frame. So you tested these and got no reading on a stator that had a red wire, a blue wire, and then a harness with yellow, white, and green? Then you ordered a stator and got one with a red, blue, and harness with white, yellow, and no green. Your question is will it work. Probably, your stator is already grounded to the frame through it's mounting bracket. Run a green from the rectifier to the frame and see what happens, I think the worst that will happen is it won't work. As I said earlier, I took my electrical system apart and thought everything was so crucial, then I discovered the stator ground could go anywhere on the frame as could the rectifier, the grounds tie together through the frame anyway. Rich

[hooklink]

many thank
firstly dont worry about your first post no offence taken lol.I am lead to belive what you have said in your second post is spot on correct the new magneto has a slight redesign and had a small metal plate fitted in it which i did not see this has taken the place of the green ground wire.I made a phone call to the surplyer of the magneto who gave me the same info all be it they did not say about grounding the green wire from the regulator to the frame so many thanks for that bit of info.Hope to have a play with it on friday so fingers crossed.I will let you know what happens
many thanks hooklink
happy christmas

[Bashan]

You still need to ground the rectifier, it's part of the smoothing circuit for the rectified red wire to the battery. Here's the color code for the rectifier:

And here's a wiring diagram for a generic 50cc, it should be close to yours; nothing is exact in the Chinese scooter industry:

Notice the rectifier at the bottom right of the diagram, it has a red, white, yellow, and green, You can check your rectifier to see if the electrics are working properly. Use your multi and test the white and yellow by touching the red probe to the wire and black probe to the frame. Both should be around 12v AC. Then test the red by touching the red probe to red (at the rectifier is the same as touching the battery), and black to frame. Crank up the RPMs and you should get about 14v DC. The green just gives the circuit a place to go, you could actually test all the wires with black probe on green, it's the same as the frame. Good luck, Rich

[hooklink]

Hi
i would like to say a big thanks to every one for their help with my magneto problem.You will all be please to know i had chance to play with it today and bingo all up and running lights work indicators work charging system works.The smile on my sons face was better than any christmas present
Many thanks again hope you all have a lovely christmas and a happy new year
ride safe
Hooklink

[Bashan]

And to you fine sir. Rich