Lifan 140 in a '64 CS90. Electrical frustration.

Mini Dirt Bikes & Pit Bikes Forum

Help Support Mini Dirt Bikes & Pit Bikes Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

sirenalx

Member
Joined
Dec 15, 2014
Messages
8
Reaction score
0
I have a '64 Honda s90 that I popped a lifan 140 into. All works, motor, head/tail, brake, and turn signals.



Problem I have is not enough voltage to charge the 12v battery(as tested while in idle @7.5v dc after it goes through the rectifier/regulator). This means that with lights on, I am running bat down, then lights go dim, and then blinkers wont work.

From motor two wires go to the cdi, white and yellow go to rectifier, and last one is neutral switch. Wired via service manual wiring diagram and hooper imports diagrams.



What gives, I need more than 7.5v to charge a 12v battery plus run lights. Help me, This is driving me nuts.
 
Welcome to miniriders,

Drop by and say hello in our Introduce Yourself thread.

Are you using a 12v regulator/rectifier ? or the original 6v one ?
And is your engine/stator etc all new ?


cheers, craig
 
new motor, cdi, coil, and rectifier/regulator. 5 wires coming out of the motor, 4 wire rectifier, 5 wire cdi, and kill switch. All 12v. All light bulbs switched over to 12v versions.
 
Last edited:
Do you have a picture of the actual reg/rect you're using, and the wiring into it ?

And do you have a multimeter?
I can tell you how to check that the lighting coils' readings are all good.
 
20141221_021159.jpg
20141220_184512.jpg20141220_184512.jpg
Yes I have a multimeter, I used it to check that my rec/reg was and is wired correctly.
Getting to the wires on the motor are impossible as to installation, will have to make jumpers, dismount motor, install jumpers, reinstall motor. All wires, rec/reg, and cdi above motor in frame. No other Access. I can say that my friend with a 90cc lifan in his ct70, has the same issue. Have not ohm'd his rec/reg out yet.
 
i haven't used one of those style reg/rect's before so i'm not sure on their internals.
But you could try swapping the yellow and the white wires around and see if it works then
The internals of that reg/rect might be set up different, so needs the 12v+ power wire to go to the pink, then the lower voltage wire to the yellow ?

I have used these 2 type's before and haven't had a problem with them, and get 12.6v at idle then the voltage increases as the revs go up.
12V Regulator Rectifier 50cc 90cc 110 125cc Dirt PIT Bikes ATV Quad | eBay
12V 4 PIN Rectifier Regulator 50cc 90cc 110cc 125cc PIT Quad Dirt Bike ATV Buggy | eBay
 
Last edited:
Ok, ive ohm'd out the rectifier and it is installed correctly. Now I contacted OORacing and sent pictures, they told me this:
"Ok you have a split phase gen running on a single phase regulators will never charge.
Sadly we can't export parts to the U.S. Any more."
Does that sound correct? if so what now?
 
They are just across Lake Washington from me. However they have gone out of business of selling lifan due to import restrictions now. They have been selling all their stock out the door as fast as possible. My friends and I have purchased 4 140's, and one 90, multiple carbs, gaskets, etc..... No more stock for what I need.
Same problem with the 90cc motor only worse. So I guess I must find said part. If I have to order that one from your area so be it.
 
bump, I will be disassembling shortly hoping to test all voltages and pic the gen to the site.
 
Update:

Still confused…
Purchased 140cc Lifan motor from hooper imports just across town from me but going out of business. Wiring into bike not so helpful expertise, but other stuff great.
Bolted it in a 1964 Honda CS90.
Converted all bulbs and battery to 12v.
All works, runs great, but after a while lights go dim, and turn signals don’t work. Recharge battery, repeat.
Ohm’d out reg/rectifier, standard import 4 wire, red, green pink, yellow.
Tested output from stator, yellow wire at 24vAC at idle, 30vAC high idle.
White wire tested 30vAC at idle, 40vAC at high idle.
Connect reg/rec, red wire out of unit produces approx 6vDC at idle, 8vDC full throttle. Tried reversing yellow and pink input, no difference. Model # HK-12V reg/rec, installed backup that is identical, same result.
Only wires I have connected to in the existing wire harness is the red power from battery, and ground from battery. Old rectifier has been removed, along with the old motor, 6v battery, and all old 6v bulbs.

What the heck is going on, it seems that the reg/rec is meant for 6v, not 12v, but it is marked 12v, along with the back up one I have. I bought a smaller reg/rec but it doesn’t ohm out the same way and I cant figure out how to wire it. It could be a wrong unit.

Anyone have some good ideas?
Large reg/rec is the one that came with the set up and I have a second identical one, the small one I cant figure how to wire and is different.

20150104_205236.jpg
 
Ok, the new regulator / rectifier is easy to wire.
As it sits in your pic, the red wire goes to the top left terminal, and the green wire to the bottom right.
The white wire goes to the bottom left, and the yellow wire to the top right.


And where did you get the big reg/rects from? I need one for my Yamaha IT200
 
Last edited:
Ok, big rec/reg I got from hooper. it is the one I can wire and works but not enough juice coming out. the small one with no wires, or markings, or directions, I cannot ohm out to find input and out puts...
 
I wrote what wire goes to what in the post above yours
 

Latest posts

Back
Top