qm50qt-3e Ignition wiring help!!! [huh] By durtturbine (Read 2,603 times)

[durtturbine]

I recently bought a SUNL qm50qt-3e 50cc scooter off of my local craigslist. Well I got it home and cleaned the carb out tried to crank it...Nothing. Opened up the scooter(Took all the cheap plastic off) and the ignition is wired ass backwards. Its crudely taped up. The busted ignition switch has 5 wires coming out where as the wires going into the harness are only 4. Here are some pictures. Could you all tell me what wire goes to each? I can Crank the scooter using this thing. 



Here are the wires going into the harness


The old ignition 


The New Ignition


My battery box...I thought there was supposed to be a "CDI"?

[JR]

First picture is the starter/solenoid relay:

2 large reds = 12Vdc from battery and 12Vdc out to starter

Red/yellow = ground wire from start button

Green/yellow = 12Vdc positive and is hot when the brake handle is applied.

The start button is the ground side of the starter relay and when pushed completes the circuit with either brake handle pressed with the key on.

The second picture is the colors of:

Red = 12Vdc from battery

Black/white = kill wire to CDI

Red/Black = Ac feed from stator to CDI

Black = 12Vdc with key turned on

Where are these wires located? You mentioned wires by the battery box for CDI?

Third Picture is key switch plug:

Red = 12Vdc from battery

Black = 12Vdc out when key is on

Black/white = engine kill wire to CDI

Green X 2 = ground

Some systems have a green coming from the battery to the key switch and with the key on a ground is sent to the engine kill switch on the handle bar and the start button to make the scooter start when the button is pressed, remember when you press the start button you are completing the circuit to start the engine by supplying the ground to the solenoid relay. Also when you turn the key off you are grounding out the CDI through the black/white wire thus killing the engine.

Fourth picture = new key switch wires

Red = 12Vdc from battery

Black = 12Vdc out with the key on

White/black = CDI kill wire with key off

green = ground wire from battery (negative)

This switch is a 4 wire key system, if you want to use it you can jump the other green in your old harness to the green on this switch, but it would be better to have the correct switch.

Fifth picture as you said your battery box area.

Have you found a CDI at all?

JR

[durtturbine]

Negative. I also posted on another forum, someone mentioned that this engine might not have a Cdi. The guy I bought it off of said it was a 1999. Also if you look at the picture of the battery box, it has one small red wire and one small black wire both crudely spliced into the battery wires. Not sure what those were for.

UPDATE: Rewired in the old ignition switch. Pulling the brake(tried both brakes) and pushed power button still does nothing. I'm at a loss right now. Dunno what else to try.

[JR]

Jan 27, 2015 8:10:25 GMT -6 durtturbine said:

Negative. I also posted on another forum, someone mentioned that this engine might not have a Cdi. The guy I bought it off of said it was a 1999. Also if you look at the picture of the battery box, it has one small red wire and one small black wire both crudely spliced into the battery wires. Not sure what those were for.

UPDATE: Rewired in the old ignition switch. Pulling the brake(tried both brakes) and pushed power button still does nothing. I'm at a loss right now. Dunno what else to try.

Got a volt meter? Need to do some tests. First one is see if we have 12Vdc on the red wire going to the key switch, if so then turn the key on and lets see if we have 12vdc on the black wire.

BTW is this a two stroke? Reason I ask is sometimes 2 bangers use the black wire as ground? Also here is the "correct" key switch:

.partsforscooters.com/Key_lock_switch" rel="nofollow" target="_blank">.partsforscooters.com/Key_lock_switch

Let's look at this  diagram it shows no CDI.

.scootusa.com/wiring_diagram_for_ts50qt_with_d.htm" rel="nofollow" target="_blank">.scootusa.com/wiring_diagram_for_ts50qt_with_d.htm

JR

[alleyoop]

Found this, plug that comes off the stator I think his stator fires the coil no cdi:


With a Ohm Meter measure the resistance of the windings. The Gray & Brown wires are about 2 ohms. The Black & White wires measure at around 150 ohms.

One set of wires are the genarator for the charging system and the other set are to fire the coil.

[JR]

Yes the 1999 model had no CDI, coil only. Found that out today.

JR

[durtturbine]

Alright. So I figured the wiring out. It will turn now but not crank. This is my first scooter ever. I've worked on cars all my life. So I'm guessing change spark plug now?

[JR]

Put the plug on the frame (ground) the old fashioned way turn her over and let's see if we have a spark?

JR

[durtturbine]

Roger that, Let me try it real quick.

[durtturbine]

Alright so I don't have a plug socket or a wrench thatll fit it. It'll have to wait till friday. Thanks for you guys help! Ill be back Friday

[durtturbine]

Alrighty, Got a spark, also took the carb apart again just to make sure i cleaned everything right. Still not cranking. Any other recommendations ?

[durtturbine]

Mk so upon further inspection it looks like there is an excessive amount of oil in the combustion chamber. Is that a normal thing with scooters or???

[JR]

She's a two stroke so it'll be oily but too much may foul the plug? Also the reed valve may be gummed up, need to see if we have any decent compression?

[alleyoop]

Can you take some pictures of the carb area, to see what kind of carb is on there. The Left side of the carb is the most important side that is where any adjustments would be .
Alleyoop

[durtturbine]

I got compression but it didn't seem like it was strong enough. I've read it's supposed to be enough to throw your thumb off. It poped it off but barely. I'll take some pics. Give me a little.