Charging Issues - Motovert RX175

[Rian]

Hello everyone,
I'm pretty new to this minibike thing, I've had a few over the years but they were just ebay ****ters and I never really cared about them, nor how they worked as long as they did actually work. Now I've recently got myself a motovert rx125, and suddenly I just want to know how everything on it works, and how to maintain it properly.
So basically the engine on this bike has been swapped from the original 125 to a Zongshen 175, and the only real problem I've had with it so far is keeping the battery charged. Now I didn't do the engine conversion so I'm just going off what I remember being told about the bike by the previous owner, and from what I've found from pulling things apart and checking. Alright here we go:
The new engine runs the same stator and I'm guessing flywheel from the last engine.
The headlight uses a 12v 35/35watt bulb.
The rear indicators are LED, the fronts are incandescent or whatever they're called.
The brake light is LED.
The parker light was some blue 12v thing, it stayed on when the headlight was on and I didn't see the point in this so I took it out in an attempt to keep charge in the battery longer when riding at night.
The battery is a Factory Effex CTX4L-BS, I'm guessing these bikes use a 12v system? I'm only new to this so i don't know.
So the problem is when I go for a ride at night, or any other time when I need the headlight, the battery begins to go flat within like 15 minutes. And as a result the readings on the digital display disappear, the indicators stop flashing and the headlight becomes very dull. And this sucks and is really quite dangerous, so today I did some tests with a multimeter to see if I could figure out the problem, here are some readings taken at the battery terminals:
Battery with everything off and engine not running: 7.8volts
Battery with engine off and headlight on: 3.9volts
When the engine is on, the battery is "charging" between 6 and 8.7volts.

Now if the bike uses a 12v system, shouldn't the battery be charging at 13v or higher?
And is the headlight meant to be drawing that much power, would changing to an LED help?
Okay so from the readings above does this mean the battery will never get over 8.7 volts? (like 70% charge if it's a 12volt battery?)
And what I'm hoping is not the issue, is the stator/regulator/etc stuffed?

And also is Shell Advance 4T 15-40 an okay oil to use in this engine? It's a mineral oil and it's the only one I could find around that wasn't synthetic or 20-50.

Any help is greatly appreciated, thanks.
Rian

 

[SnItChY]

you oil is fine , use it


as for charge , your battrey sounds like its stuffed , when you measure the charge was it from the battery terminals when bike was running??

get a new battery first not a ebay craP go to a battery place

also run your headlight useing ac power not dc as is what you have

to do this you need to run a wire from your yellow charge wire b4 it goes into the reg
this will freeup power draw on your battery , but headlight will only work when motor is running and will dim a lil at idle

if you do this with a new battery , your problem will be solved ,

 

[Rian]

Yeah I measured the charge from the battery terminals when the engine was running, and it was ~8volts, I was expecting it to be up around 13-14volts like on cars.
To run my headlight on AC do I need a stator with multiple outputs? I'm assuming the one on there currently has multiple outputs due to how many wires are coming out of it, is there a way to check this? And the same headlight bulb will be fine to handle AC instead of DC yeah?
Thank you heaps for your help, I'll go and have a look at it now,
Rian.

 

[motoluver]

Had tge same problem with my rx140 wuth tge battery goin flat after 15 mins of night riding. Replace the battery with a better aftermarket one. Stock onees are junk.

 

[SnItChY]

your stator will be ok , but the best way to run a headlight on a motorcycle is from the ac on the stator ,

like i said look at the wires coming out of the stator 1 will be yellow that goes to a reg/rec , splice a wire into that wire b4 it goes to your reg/rec

then run that wire up to the headlight , ac power will be fine for your current globe

the idea of running a headlight from ac power is to free up power on a small battrey , stops the rapid decharge , and recharge what kills battery over time

on my bike the headlight runs from ac power , all the rest of my lights run off the battery , my battery is now over 3 yrs old and still holds good charge

yes measure your charge wire b4 it goes to your reg/rec with a multi meter and then see what you have with the bike running

also measure charge at battery , should be around 12v at idle and up to 13/14 at full revs

 

[motoluver]

Had tge same problem with my rx140 wuth tge battery goin flat after 15 mins of night riding. Replace the battery with a better aftermarket one. Stock onees are junk.

 

[Rian]

The battery is already an aftermarket one, but I was thinking of replacing it anyway as I initially suspected this to be the problem. So when I splice the yellow wire, does it need to split into 2 wires with one going to the headlight and one to the reg? or do I just redirect this yellow wire so it only goes to the headlight, and remove the original wire that used to supply power to the headlight from the battery?
I also have a feeling the charging system is not working properly, I kept getting readings of 7.5-8.5 volts at the terminals when the engine was running, I'll look into this properly tomorrow when I can actually see what I'm doing in my shed. Hopefully a new battery and AC to the headlight will solve the problem.
Thanks, Rian.

 

[Minibiker05]

hey mate those reading u were getting where they at idle coz it wont start charging at full 13-14v till its about over 2000rpm+

 

[Rian]

Yeah those readings were at idle, and the volts did increase when I revved it, I didn't rev it too high because it's heaps noisy, but the volts didn't really increase all that much with revs. I was expecting a higher voltage at idle, something like 12volts. So you're saying the engine is only charging when it's got some revs on? Wouldn't there have to be a huge increase in voltage through the revs for the battery to actually charge if it is only charging 8volts at idle, it would have to increase by at least 4 volts before it actually started charging? I don't know very much about this sort of thing so I'm probably wrong, but that sounds like a large increase. Wouldn't this suggest something is not working properly in the charging system? I really appreciate all of your input by the way, I'm keen to get this sorted.

 

[Minibiker05]

yer its works like an alternator in a car man try it tomoz let it idle then hold it at half throttle and see if it goes high enoguh

 

[Rian]

Okay I'll give that a go, cheers mate.
Can anyone tell me if the yellow wire from the stator needs to go to the headlight as well as the reg, or just just to the headlight and remove the original connection to the reg?

 

[SnItChY]

split it , then run a wire to headlight and the reg/rec , the reg/rec takes the ac power your stator produces and turns it dc pwer to charge the batt

you will need to rev her up a bit to get a charge , but yours does seem low at low revs , see how you go , but i recon it will be fine with what i have told you

 

[Rian]

Okay I'll get stuck into it tomorrow, and then I'll post up here with the results.
Thanks heaps everyone,
Rian.

 

[Rian]

Okay, so I've split the yellow wire from the stator, one part of it goes to the reg/rec thingy, and I'm having issues finding where the other end goes. The wiring loom is confusing me and I don't want to start disconnecting wires because I know I'll get stuffed up and forget where they go.

Okay my question is: do I run the other end of the split yellow wire to the switch for the light, or to somewhere else before it reaches the switch? And there are 4 wires connected to the switch, I'm guessing one is for the backlight in the display, one is for the parker light and taillight, one is for the headlight(which then runs into a highbeam/lowbeam switch), and one is from the battery?
The problem is I have no idea which one is which, I've tried testing it with a multimeter but I could not get a reading for some reason. So should I just run this new wire to the switch, and which wire do I replace with this new wire?

OR

Do I just run the new wire straight to the highbeam/lowbeam switch(bypassing the actual light switch) so that the headlight is always on while the bike is running? As then the ac power would run only the headlight and not all the other things like taillight, backlight for display etc. But then there are still three wires going into the highbeam/lowbeam switch, probably one being power into the switch, and the other two being power out to the highbeam or the lowbeam. but again I don't know which one is which?

Sorry for all the n00b questions, and thanks to anyone that can help.
Rian

 

[Rian]

Okay I've solved it, I ran the yellow AC wire straight to the highbeam/lowbeam switch, bypassing the main light switch, so the headlight is always on. It's still fairly dull but better than no headlight. Hopefully my battery will hold charge now if it isn't already stuffed. I hope I've done this right, it seemed to be working okay just then when I took it for a spin. Have other people wired it so the headlight is constantly on?
Also thanks to everyone who helped out.