Electrical Issue on 50cc Chinese Scooter

roberto188 · 05-10-2024, 11:47 AM

My little 50cc Chinese scooter will not charge the battery. It kick starts just fine and runs just fine, but the battery will not charge. I disconnected all my wiring, installed a new regulator and started my scooter. The output of the regulator was reading around 14-15 volts. Once I started plugging in my other components the voltage output from the regulator went to 0. I believe it burned the regulator out as it was very high when I took it out. I disconnected all my wiring again, installed the old regulator and started the scooter. The regulator was putting out only around 11 volts, 12 max, with high RPMs. I then plugged my other wiring back in and the output of the regulator dropped to 7 volts. I check the stator output and it reads about 20-30 volts at idle and 40-60 volts at high RPMs. Does anyone have any idea what the problem could be? Is my stator just undersized to power all my accessories and charge the battery, or is there maybe a short somewhere?

sc00ter · 05-11-2024, 10:59 AM

I'll tell you a funny story. I had a Yamaha Zuma 125, the newer EFI model. I bought some heated grips, I forgot the brand, but they had a "confirmed fitment" for my scooter on the manufacturers website. Oxford, that was the brand! Anyways, they fit just fine BUT if I had them on the high setting and came to idle the scooter would stall and NOT restart. It turns out I was supposed to turn the grips down when coming to a stop as the stator didn't put out enough power at idle to power them on the high setting.

I quit using heated grips after that B.S. and now use heated gloves instead. There is a way to measure the stator output (I saw a how-to on YouTube) and then you multiply that with the draw of you accessories. You can put a larger output stator on, and I've know a few people who have successfully done this.

Does you scooter have a inline fuse going to the battery? I had one blow on a Zuma 50cc and never knew there was a fuse there. Everything worked but the battery was constantly dying after being charged. Check the fuse and make sure it the correct fuse.

roberto188 · 05-13-2024, 08:38 AM

Thanks for the reply and story. It does have an inline fuse and it's all good. I checked it a few times. I'm going to replace the regulator 1 more time, see if that does the trick. If it shorts out another regulator I think I can confirm that there is a wiring issue in my dash/handlebar area where all my panel lights and head lights are wired. Any other advice would be appreciated.

sc00ter · 05-13-2024, 09:42 AM

I hate electrical issues so bad! I'm not very electrical smart but YouTube has helped me learn a little bit at a time.

I have a friend with a Zuma 2-stroke. He has crashed it at least 3 times and it has a few random electrical issues. I refuse flat-out to even look at that scooter. Crash damage is the worst to diagnose and he can't understand that the weekend is my time, and I'm not using my time working on a smashed up scooter.

I'm not 100% sold on a bad voltage regulator. Tap into the stator with a volt meter that records spikes over a set level. You find out what the max output is on the stator, set the recording volt meter to that max output while its hooked up and go for a ride. If it spikes over the set level it will record the max spike output. It's rare but a stator can spike from a bad winding and short out related components. You replace said components and the same problem repeats. I had a bad stator on a CBR900RR that kept zapping the voltage regulator. I worked at a tuning shop at the time and the owner taught me how to trouble shoot it, plus it was a kinda known issue with that model year Honda.

I've also chased broken/grounding/shorted wires in a loom and its never fun but it needs to be done. Keep us updated on any findings and feel free to continue to ask questions. Over the internet diagnostics and be a bit difficult but anything helps sometimes.

05-11-2024, 10:59 AM	#2
sc00ter Join Date: May 2017 Location: Norfolk, VA Posts: 607	I'll tell you a funny story. I had a Yamaha Zuma 125, the newer EFI model. I bought some heated grips, I forgot the brand, but they had a "confirmed fitment" for my scooter on the manufacturers website. Oxford, that was the brand! Anyways, they fit just fine BUT if I had them on the high setting and came to idle the scooter would stall and NOT restart. It turns out I was supposed to turn the grips down when coming to a stop as the stator didn't put out enough power at idle to power them on the high setting. I quit using heated grips after that B.S. and now use heated gloves instead. There is a way to measure the stator output (I saw a how-to on YouTube) and then you multiply that with the draw of you accessories. You can put a larger output stator on, and I've know a few people who have successfully done this. Does you scooter have a inline fuse going to the battery? I had one blow on a Zuma 50cc and never knew there was a fuse there. Everything worked but the battery was constantly dying after being charged. Check the fuse and make sure it the correct fuse.
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05-13-2024, 09:42 AM	#4
sc00ter Join Date: May 2017 Location: Norfolk, VA Posts: 607	I hate electrical issues so bad! I'm not very electrical smart but YouTube has helped me learn a little bit at a time. I have a friend with a Zuma 2-stroke. He has crashed it at least 3 times and it has a few random electrical issues. I refuse flat-out to even look at that scooter. Crash damage is the worst to diagnose and he can't understand that the weekend is my time, and I'm not using my time working on a smashed up scooter. I'm not 100% sold on a bad voltage regulator. Tap into the stator with a volt meter that records spikes over a set level. You find out what the max output is on the stator, set the recording volt meter to that max output while its hooked up and go for a ride. If it spikes over the set level it will record the max spike output. It's rare but a stator can spike from a bad winding and short out related components. You replace said components and the same problem repeats. I had a bad stator on a CBR900RR that kept zapping the voltage regulator. I worked at a tuning shop at the time and the owner taught me how to trouble shoot it, plus it was a kinda known issue with that model year Honda. I've also chased broken/grounding/shorted wires in a loom and its never fun but it needs to be done. Keep us updated on any findings and feel free to continue to ask questions. Over the internet diagnostics and be a bit difficult but anything helps sometimes.
	0