Znen ZN250T-D Running Rough + Headlights

blackout · 06-25-2016, 08:16 PM

Hi Scoot Dawgs,
I've been painstakingly researching, attempting to fix this scooter for about a year now, and at one point almost left it beside a dumpster. I think it's time I ask for help. All help is much appreciated.

I have a Znen ZN250T-D, and the initial issue was a broken belt. Afterwards I replaced the melted rollers, destroyed variation disk fan, shredded belt, and terrible black coolant that came with the scooter. But unfortunately the scooter seems to be running rough.

TLDR:
1. If you watch this video you will notice a constant squeaking coming from the CVT transmission, and the RPMs seem to fluctuate as the bike feels like it's struggling to stay at a steady idle.
2. The scooter does not die during idle.
3. Does not feel like it's running rough while riding or at higher RPMs.

Anybody have any idea what the issue might be?

PS: Also the headlights do not work anymore. The low-lights work, but not the switchable brights. This happened when I was replacing the coolant. I might have spilled a bit of the coolant on a connection, and I am unsure how to diagnose the issue.

Ebuddy · 06-26-2016, 12:15 AM

Sounds like the belt isn't running smoothly over the clutch assembly. Perhaps something hinky with the clutch itself or something in the gear box that's not turning properly at low rpm but does OK at higher RPM? As for the electrical issue, that's one thing I understand least. ;-)

Shadowfire · 06-26-2016, 02:56 AM

A little bit of coolant on the wires is NOT responsible for the lack of high beams.
Check the connectors at the high beam/flash to pass switches, and the connector under the front cowling that powers the lights.
Having said that, there is also the possibility that the high beam filaments are out, but (on a Chinese scooter) my money is on the shitty factory wiring.

As for the CVT, have you taken off the bell housing and examined the centrifugal clutch? Someone else may be able to shed more insight as to why the idle is all over the place.

blackout · 06-26-2016, 07:42 PM

Quote:

Originally Posted by Shadowfire

A little bit of coolant on the wires is NOT responsible for the lack of high beams.
Check the connectors at the high beam/flash to pass switches, and the connector under the front cowling that powers the lights.
Having said that, there is also the possibility that the high beam filaments are out, but (on a Chinese scooter) my money is on the shitty factory wiring.

As for the CVT, have you taken off the bell housing and examined the centrifugal clutch? Someone else may be able to shed more insight as to why the idle is all over the place.

Well... coolant isn't exactly water, and I can only imagine residue being left behind after some of the water evaporates. I may be mistaken to mention this memory, but I do recall the lights turning on on their own after spilling some coolant. Parton my naivety, but Could CDI need replacing?
Also I did check the filaments and they are fine.

Quote:

Originally Posted by Ebuddy

Sounds like the belt isn't running smoothly over the clutch assembly. Perhaps something hinky with the clutch itself or something in the gear box that's not turning properly at low rpm but does OK at higher RPM? As for the electrical issue, that's one thing I understand least. ;-)

Good call, I tightened the nuts on both variators and it seemed like it helped with noise. It must have been a bit loose. I haven't gone for a test ride yet so I will return with an update soon.

Also I replaced the gasoline and the bike seemed like it was running much better. The gasoline had to have been a few months old and lost a significant amount of octane.

Irish · 06-27-2016, 04:39 PM

I'm far from a SCOOTER mechanic but it seems as if you have a belt problem. Either in the size or the tension.
As far as the fuel goes-old or new gas will make a Hell of a difference. I have even seen a motorcycle that the owner couldn't start. He finally put in NEW gas & it started right up!

Irish

blackout · 07-02-2016, 08:23 PM

Alright, so I am still stumped on the headlights. ALTHOUGH, I did notice the high-beam indicator does not light up when I flip the switch. I also tried by-passing the the switch to no avail.

I checked the fuses and all other connections and couldn't find anything out of the ordinary. Any suggestions? I also have a multi-meter so if anybody can help me out with what connections to try out and what results to expect. I am able to do this.

Here is the electrical diagram:
http://screencloud.net/v/oc69

This is another off topic question, is the 'sense organ' on the diagram the alarm system? Because I found the alarm module disconnected. I do not care to have it installed either.

Shadowfire · 09-04-2016, 04:54 AM

The way your bike is wired, is:
1. The BATTERY(-) terminal is grounded to the chassis. GREEN(G) is also grounded to the chassis.
2. The BATTERY(+) terminal goes through a 15A main fuse, then travels to the MAIN SWITCH on the RED(R) wire.
3. The MAIN SWITCH (ignition) connects the RED(R) main fuse wire to the BLACK(B) ignition switched power wire (when the ignition is on).
4. The BLACK(B) wire goes to the fuse box to power the fused circuits.
5. The WHITE/RED (W/R) wire from the fuse box distributes the power to the brake light, horn, emergency flasher, blinkers, and instrument cluster. Not the fuse that you're interested in.
6. The BLACK/GREEN (B/G) wire from the fuse box powers the electronic ignition and the radiator fan. Again, not the fuse that you're interested in.
7. The BROWN/BLUE wire from the fuse box goes to what is labelled as the "RIGHT SWITCH" but I believe to be the left side handlebar switch.
8. The BLUE wire delivers power to the high beam, the WHITE wire delivers power to the low beam.

With the ignition "ON" you should be reading ~12V on the BROWN/BLUE wire, and either the BLUE or WHITE wire, depending on the headlight switch settings. You said that the low beams work, so you MUST be getting voltage on the BROWN/BLUE wire.

So the next thing I'm going to ask you to do, is to run a jumper a wire (20 AWG or larger) between the BROWN/BLUE wire and the BLUE wire and turn on the ignition. DO NOT LET THE EXPOSED CONTACTS SHORT TO THE CHASSIS WHILE THE IGNITION POWER IS ON (or you will be replacing fuses). If the high beams come on, check that the blue wire's connector is making a firm contact, then replace the switch assembly. If the high beams don't come on, you either have a blown high beam filament, or a break in the BLUE wire - check for voltage on the blue wire entering the headlight socket on the front cowling.

Also, 11.2V is a really discharged state for the battery. You should put it on a charger.

blackout · 09-04-2016, 06:20 AM

Quote:

Originally Posted by Shadowfire

So the next thing I'm going to ask you to do, is to run a jumper a wire (20 AWG or larger) between the BROWN/BLUE wire and the BLUE wire and turn on the ignition. DO NOT LET THE EXPOSED CONTACTS SHORT TO THE CHASSIS WHILE THE IGNITION POWER IS ON (or you will be replacing fuses). If the high beams come on, check that the blue wire's connector is making a firm contact, then replace the switch assembly. If the high beams don't come on, you either have a blown high beam filament, or a break in the BLUE wire - check for voltage on the blue wire entering the headlight socket on the front cowling.

Wow!

I love you.
The first thing I tried just now was connecting the BROWN/BLUE wire to the BLUE wire, turned on the ignition, and the high beam was working!

I will correct myself from earlier, when I mentioned 'green' wire I meant to say 'dark green'.
Is there a possibility that the dark green wire has a break somewhere? Because it doesn't seem to make any readings with negative or positive terminal of the battery. Perhaps when the switch connects the blue + dark green, it may not be completing the circuit.

[edit] I just tested the switch again and I am most certain it is working as needed. To prove it, with the switch uninstalled, I put a jumper from the green wire to the blue wire and the high beams did not work.
I can't quite figure out where the green wire leads to since it is wrapped up in a huge bundle that follows into a difficult part of the bike to get to.

blackout · 09-04-2016, 09:27 PM

Solved:
I started the engine and the highbeam headlights started to work. This didn't work before so I must have corrected the connection somewhere when putting everything back together.
Also is it normal for the highbeam not working if the engine isn't running?

Shadowfire · 09-04-2016, 09:39 PM

That depends on how the bike is wired. On my 50cc scooter, the headlights are wired on a separate circuit from the ignition power, and are only powered by the generator from the engine.

On my maxi-scooters, the headlights are wired to the ignition power and come on as soon as you turn the key to the run position. The wiring diagram you posted suggested that it was the latter type of wiring. This means that (surprise, surprise) your bike isn't wired exactly the same as the diagram.

06-26-2016, 12:15 AM	#2
Ebuddy Join Date: Jun 2013 Location: Minnesota Posts: 73	Sounds like the belt isn't running smoothly over the clutch assembly. Perhaps something hinky with the clutch itself or something in the gear box that's not turning properly at low rpm but does OK at higher RPM? As for the electrical issue, that's one thing I understand least. ;-)
	0

07-02-2016, 08:23 PM	#6
blackout Join Date: Jun 2016 Posts: 7	Alright, so I am still stumped on the headlights. ALTHOUGH, I did notice the high-beam indicator does not light up when I flip the switch. I also tried by-passing the the switch to no avail. I checked the fuses and all other connections and couldn't find anything out of the ordinary. Any suggestions? I also have a multi-meter so if anybody can help me out with what connections to try out and what results to expect. I am able to do this. Here is the electrical diagram: http://screencloud.net/v/oc69 This is another off topic question, is the 'sense organ' on the diagram the alarm system? Because I found the alarm module disconnected. I do not care to have it installed either.
	0

09-04-2016, 04:54 AM	#7
Shadowfire Join Date: Feb 2015 Posts: 121	The way your bike is wired, is: 1. The BATTERY(-) terminal is grounded to the chassis. GREEN(G) is also grounded to the chassis. 2. The BATTERY(+) terminal goes through a 15A main fuse, then travels to the MAIN SWITCH on the RED(R) wire. 3. The MAIN SWITCH (ignition) connects the RED(R) main fuse wire to the BLACK(B) ignition switched power wire (when the ignition is on). 4. The BLACK(B) wire goes to the fuse box to power the fused circuits. 5. The WHITE/RED (W/R) wire from the fuse box distributes the power to the brake light, horn, emergency flasher, blinkers, and instrument cluster. Not the fuse that you're interested in. 6. The BLACK/GREEN (B/G) wire from the fuse box powers the electronic ignition and the radiator fan. Again, not the fuse that you're interested in. 7. The BROWN/BLUE wire from the fuse box goes to what is labelled as the "RIGHT SWITCH" but I believe to be the left side handlebar switch. 8. The BLUE wire delivers power to the high beam, the WHITE wire delivers power to the low beam. With the ignition "ON" you should be reading ~12V on the BROWN/BLUE wire, and either the BLUE or WHITE wire, depending on the headlight switch settings. You said that the low beams work, so you MUST be getting voltage on the BROWN/BLUE wire. So the next thing I'm going to ask you to do, is to run a jumper a wire (20 AWG or larger) between the BROWN/BLUE wire and the BLUE wire and turn on the ignition. DO NOT LET THE EXPOSED CONTACTS SHORT TO THE CHASSIS WHILE THE IGNITION POWER IS ON (or you will be replacing fuses). If the high beams come on, check that the blue wire's connector is making a firm contact, then replace the switch assembly. If the high beams don't come on, you either have a blown high beam filament, or a break in the BLUE wire - check for voltage on the blue wire entering the headlight socket on the front cowling. Also, 11.2V is a really discharged state for the battery. You should put it on a charger.
	0

09-04-2016, 09:27 PM	#9
blackout Join Date: Jun 2016 Posts: 7	Solved: I started the engine and the highbeam headlights started to work. This didn't work before so I must have corrected the connection somewhere when putting everything back together. Also is it normal for the highbeam not working if the engine isn't running?
	0

09-04-2016, 09:39 PM	#10
Shadowfire Join Date: Feb 2015 Posts: 121	That depends on how the bike is wired. On my 50cc scooter, the headlights are wired on a separate circuit from the ignition power, and are only powered by the generator from the engine. On my maxi-scooters, the headlights are wired to the ignition power and come on as soon as you turn the key to the run position. The wiring diagram you posted suggested that it was the latter type of wiring. This means that (surprise, surprise) your bike isn't wired exactly the same as the diagram.
	0