Charging problems

heftynoma

heftynoma

Member
I purchased a second 125 manual engine and I am having some issues with charging and lights.
2 yellow wires from engine. Neither have ground by themselves so i wired 1 to ground and the other I wired to the white AND yellow from the frame harness.
If I unhook the battery it's only outputting 6v.
If I set my multimeter to 200 ohms both of my engines read 30 on the multiMeter across the 2 yellow wires from engine.
I read that mike had issues with a pink and yellow stator before and I read one other post from 2 years ago were something similar happened.
Could it just be a junk stator?
 
heftynoma said:
I purchased a second 125 manual engine and I am having some issues with charging and lights.
2 yellow wires from engine. Neither have ground by themselves so i wired 1 to ground and the other I wired to the white AND yellow from the frame harness.
If I unhook the battery it's only outputting 6v.
If I set my multimeter to 200 ohms both of my engines read 30 on the multiMeter across the 2 yellow wires from engine.
I read that mike had issues with a pink and yellow stator before and I read one other post from 2 years ago were something similar happened.
Could it just be a junk stator?
Click to expand...
Is the engine you bought meant to be 12V? I believe the lifans are, but I could be wrong on that.

You need to know what configuration your stator is set up in. Usually if it's delta wye or star it'll have 3 white or yellow wires coming out of it. If it only has the 2 it's usually just a single phase.

If it's just the two, and they're 6V, one needs to go to pink on the harness and the other needs to go to yellow, no grounding anything. Don't use white because that gets turned on and off by the headlight switch.

Let us know more when you get a minute. - Kyle
 
The two yellow wires are usually the two legs coming from your stator that produce AC power. They should be connected to a 4 wire regulator/rectifier. That should provide 12 volt power for coil, lights, horn, and keep your battery charged.
 
I'm having the same kind of issue, I have recently installed a lifen type 125 in my K0, and all is well but the lighting just isn't quite right. This motor has 2 yellow wires coming out instead of 1, and I wasn't sure if they both do the same job or not. I have a brand new 12V battery, and all 12V bulbs.

In the 1st key on position, the tail light does not come on, but the brake light works, but gets brighter while reving...

The 2nd key position, the tail light comes on, but it’s very bright...The head light, a 25w/25w, comes on dimly, brightens with rev's and after a few seconds it blows.....the speedometer lights/and neutral, get very bright and have blown, but seem to last much longer. Also the battery remains at a constant 12.7V , should it not go higher when reving if it's charging properly? I’m using a stock K0 wiring harness, and a 12v ½ wave rectifier.
Do I possibly have those two yellow wires mixed up? or is there something else going on here. I'm out of ideas at this point. Any help is much appreciated.
 
Have you checked the generic wiring diagram for clone motors. How do you know you've got a half wave rectifier? If your lights are too bright and you're blowing fuses, your rectifier isn't wired correctly.
 
Oaker57 said:
I'm having the same kind of issue, I have recently installed a lifen type 125 in my K0, and all is well but the lighting just isn't quite right. This motor has 2 yellow wires coming out instead of 1, and I wasn't sure if they both do the same job or not. I have a brand new 12V battery, and all 12V bulbs.

In the 1st key on position, the tail light does not come on, but the brake light works, but gets brighter while reving...

The 2nd key position, the tail light comes on, but it’s very bright...The head light, a 25w/25w, comes on dimly, brightens with rev's and after a few seconds it blows.....the speedometer lights/and neutral, get very bright and have blown, but seem to last much longer. Also the battery remains at a constant 12.7V , should it not go higher when reving if it's charging properly? I’m using a stock K0 wiring harness, and a 12v ½ wave rectifier.
Do I possibly have those two yellow wires mixed up? or is there something else going on here. I'm out of ideas at this point. Any help is much appreciated.
Click to expand...
What harness and key switch are installed in the bike?
 
Oaker57 said:
It's a K0 switch, a new stock harness and a Trail Buddy stock to 125 conversion harness...(I can't recall the part number right now) But I know I connected 1 yellow to the lighting yellow...and the other yellow to the white....I will try to find that part number
Click to expand...
Ok. Sorry, I won’t be much help. I never use the stock harness. I prefer to go with the Trail Buddy simple 12v harness. It’s completely plug-n-play for 12v engines. Way easier than dealing with the sub harness.
As for the two yellows on the engine. I’ve found they need to be wired like this:
One of the engine yellows gets connected to chassis ground.
The other engine yellow is connected TOGETHER with both the yellow and white of the harness.
It doesn’t matter which engine yellow goes where.
 
MiniBike Mike’s Garage said:
Ok. Sorry, I won’t be much help. I never use the stock harness. I prefer to go with the Trail Buddy simple 12v harness. It’s completely plug-n-play for 12v engines. Way easier than dealing with the sub harness.
As for the two yellows on the engine. I’ve found they need to be wired like this:
One of the engine yellows gets connected to chassis ground.
The other engine yellow is connected TOGETHER with both the yellow and white of the harness.
It doesn’t matter which engine yellow goes where.
Click to expand...
Thanks Mike, grounding one of the yellows seems to be the logical answer... I have to get a new hedlight bulb, and will get back to it this weekend. I will report back what I find out....Appreciate your help.
 
Oaker57 said:
Thanks Mike, grounding one of the yellows seems to be the logical answer... I have to get a new hedlight bulb, and will get back to it this weekend. I will report back what I find out....Appreciate your help.
Click to expand...
Just for reference here on the harness, I found my paperwork, and I used the Trail Buddy "TB421-Lifen Tandem Harness", along with the stock one...But I will report back, once I switch the 2 yellow wires around, as you suggested.
 
I have two of the exact same chinese amazon engines with the same stator. Here's a picture I found online.I labeled them 1, 2 and 3.
My first engine I have wired like #3 but I'm using a full wave rectifier and that's the only way it'll charge.
My other engine is wired like #1 also with a full wave rec. They both make 14.5 volts like this. When I had the wires backwards the bike only produced 6.5 volts
I hope this helps. It makes zero sense. But try options 1 and if that doesnt work try option 3 with a full wave rectifier.
1000006815.jpg
 
heftynoma said:
I have two of the exact same chinese amazon engines with the same stator. Here's a picture I found online.I labeled them 1, 2 and 3.
My first engine I have wired like #3 but I'm using a full wave rectifier and that's the only way it'll charge.
My other engine is wired like #1 also with a full wave rec. They both make 14.5 volts like this. When I had the wires backwards the bike only produced 6.5 volts
I hope this helps. It makes zero sense. But try options 1 and if that doesnt work try option 3 with a full wave rectifier.
View attachment 84954
Click to expand...
Thanks, I definitely have a 1/2 wave, so I will try the grounding of one yellow wire first, and see how that works out. Otherwise i will try these options. I appreciate you putting this together.
 
Oaker57 said:
Just for reference here on the harness, I found my paperwork, and I used the Trail Buddy "TB421-Lifen Tandem Harness", along with the stock one...But I will report back, once I switch the 2 yellow wires around, as you suggested.
Click to expand...
Ok guys, I went with the grounding of one of the yellows method, and it's seems to be the solution. Lights are working normally, and the battery is now charging...Woo-hoo !! Thanks to all that chimed in, and for all your help.
 
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