How to wire up a QT50 with no harness??

Dustin Schings /

I have this MA50/QT50 that I am trying to wire up for the basics, but the harness is beyond repair completely. Below are the photos of what I have, I know I am missing a coil.

The engine has a plug coming out with 4 wires in in, as well as a single black wire.

20190403_130114.jpg

Here are all of the components I pulled from the crumbling harness, less a coil that was missing. Can anyone tell me or point me to a chart that will tell me how to hook all this back up? No lights are needed at all, just a kill switch.

One harness in this photo is just the female end of the motor wire/plug so I can use that when building my new harness.

20190403_130211.jpg

Re: How to wire up a QT50 with no harness??

Re: How to wire up a QT50 with no harness??

Dustin Schings /

I have that diagram but a lot of wire colors and stuff does not seem to match up. What is the black box in my photo above? I thought it was the CDI but I see there is supposed to be a "Control unit" as well.

What parts do I have in my photo above?

Re: How to wire up a QT50 with no harness??

From what I see on that diagram , the box on the right is a CDI and the smaller with the hole in it is a rectifier . Not sure what the littlest box is , possibly a diode , but ???

Re: How to wire up a QT50 with no harness??

Dustin Schings /

The smallest piece is the rectifier and has the diode logo on it. Had to scrape some more dirt off to see that. So not sure what the green one with the hole is now, maybe the light regulator?

What does the "control unit" look like?

Re: How to wire up a QT50 with no harness??

Dustin Schings /

Found my control unit. I think I can whip up a harness at this point. Thanks!!

Re: How to wire up a QT50 with no harness??

Dustin Schings /

I have reduced the wiring diagram down to minimal needed I think. "Lights" are just options.

Can someone tell me what to do with the three wires going to the "Main Switch"? I believe they just need to all be touching for the bike to start?

Also, a kill switch would just need to touch that black/red striped wire to Ground, right?

reducedQT50diagram.jpg

Re: How to wire up a QT50 with no harness??

Dustin Schings /

Any one able to confirm the condensed harness I uploaded is true and workable? I want some kind of approval before I start wiring up a harness out of nothing :)

Re: How to wire up a QT50 with no harness??

Yes it looks good, Just be sure the grounds you build all conglomerate together at a central point bolted to the motors body, not the frame.

The white black frome the control unit would be the kill switch. Just let those three dangle open till you need to investigate.

Now GO man!

Re: How to wire up a QT50 with no harness??

Dustin Schings /

> cheetahchrome . Wrote:

> -------------------------------------------------------

> Yes it looks good, Just be sure the grounds you build all conglomerate

> together at a central point bolted to the motors body, not the frame.

>

> The white black frome the control unit would be the kill switch. Just

> let those three dangle open till you need to investigate.

>

> Now GO man!

Thanks! I think I will build this up today!

Re: How to wire up a QT50 with no harness??

Hey Dustin,

Not sure if you're still working on this but I think the green block with the hole in it is the Rectifier. Also notice on the diagram you made that the Rectifier has 2 connectors on the stick line picture.

IMG_20191020_103422636.jpg
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