QT50 - Ignition/Starting

Most of the forums I've searched are pretty old, but I'm going to give this a shot.

I bought a running 79 QT50 a couple weeks ago. Guy didn't have a key for the ignition, a title, or a battery; which I still have to figure out the title issue, but I test drove it and we made a deal. I'm completely new to mopeds but the forums have helped me out so far.

So my issue is, when I got it, it had no working lights on it whatsoever. Not even the headlight when it was running. All the bulbs seem fine. He gave me an extra ignition switch with no key since the one on it was jacked up. I put the new switch on and got a new battery and fully charged it. I disassembled the switch and made the connection, and the oil light came on. Right turn signal worked front and rear, left signal just lit the light on the cluster. Tail/brake light wouldn't work either. But it wouldn't start, if I undid the connection on the switch it would start. Is there something else that may be unplugged? I checked everything over and all the bulbs and everything seems to check out. I'm at a loss here. Any help is appreciated, thanks guys.

Re: QT50 - Ignition/Starting

Your headlight has a pretty good chance of being burned out. As for the other bulbs, running without a battery isn't good for them, but I imagine they will be okay. You'll need to have the bike running and a charged battery to get a good judgement of what does and doesn't work, bulb wise.

Does your speedometer assembly have "Off, Start, and Run" above the key? The three positions have a rev limiter(which someone who understands better than I can explain) for the start position that can keep the bike from starting if wired incorrectly.

Re: QT50 - Ignition/Starting

'79 should just have run/off positions.

Re: QT50 - Ignition/Starting

Jesus. It's like I didn't even read your post. My bad. I imagine Mr. Rutherford, whose screen name I cannot remember, will have an intelligent answer.

Re: QT50 - Ignition/Starting

Did you take those bulbs out and verify that they are 6v lights? I'd just replace them anyways... cheap insurance for someone to see you when you get out riding.

Re: QT50 - Ignition/Starting

I'll take all the bulbs out and check. The ones I did check seemed fine but I will get all new 6 volt bulbs. The right signal didn't even blink, just lit up the bulb on the cluster. I'm still not sure why it wouldn't start with the ignition on. As soon as I unhook it, it starts on the first kick.

I've heard those headlights are expensive. I saw there is a way to bust out the old one at put in a new one? I'll find another thread on that.

Re: QT50 - Ignition/Starting

Jack Rutherford /

Oh man, the pressure is on

Re: QT50 - Ignition/Starting

Jack Rutherford /

maybe pics of the wiring with and without ignition switch would help - I assume you mean ignition cylinder where the key goes in. My bet is you don't have that ignition cylinder wired in right. On the express, you just have to connect the red and black wires to bypass the ignition cylinder (or if you don't have one), if memory serves. It's been awhile but the qt can't be much different. I wouldn't worry about the lights/bulbs until you get it started but the headlight and tail light are probably blown because of no battery or completely dead battery. (edited)

Re: QT50 - Ignition/Starting

The battery is brand new and fully charged. I took the old ignition cylinder out and replaced it with a new one, connected back the same. If it's in the off position it starts right up. I took apart the cylinder and put the part that turns to the terminals how it would be with the key in the on/run position. The working turn signal lit up then, but I went to kick start it and nothing. So my main question is, why would it not start with the "key" in the on/run position?

Re: QT50 - Ignition/Starting

Jack Rutherford /

That's a puzzler. Is the kill switch wire black/white on the qt50? I've been dealing with Honda Express wiring lately so sorry. Anyhow maybe something is grounding out your kill switch wire when the key is in the on position. Or maybe something is up with the new cylinder and you have it opposite how it should be. Is your new cylinder a 3 position switch or two? Maybe you answered that already. I'll look.

Re: QT50 - Ignition/Starting

I believe it's a two position. From what I've read I think the kill switch is black/red? I'm not sure. I don't think I can have the cylinder flipped. It just has three contacts in a triangle opposed from each other on each side.

Re: QT50 - Ignition/Starting

I got some pictures of how the ignition is wired in behind the head light. Ignition is the loom on the right from the two that come in from the driver side of the light. And also how I took the cylinder apart to make the connection like I had a key. On my way to the parts store to see if they have bulbs. (edited)

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Re: QT50 - Ignition/Starting

Update, I turned the white plastic piece a littler further to where the oil light was still on and it fired up. I put in a new brake light and nothing. So I think I just need to get an ignition cylinder with a key and a blinker relay, because it doesn't click with the side not working. I'll look into the brake issue later tonight.

Re: QT50 - Ignition/Starting

Jack Rutherford /

FWIW, I once bought a Honda Express that the previous owner had wired in a qt50 ignition cylinder. This leads me to believe the opposite could be done with an Express ignition in a qt. You can find them for $18 or so on ebay. qt50 ignition cylinders are much more pricey.

Re: QT50 - Ignition/Starting

My bad, Jack. Didn't mean to over hype you.

Re: QT50 - Ignition/Starting

On the 84 I had, I ended cutting and splicing in a used MJ50 ignition key switch into the harness. Mine was three position, though. Different wires soldered to the contacts on the original. I could not find on a generic one with the same. The brown is turn signal/horn , grey is oil light, if I remember right. Red and black with red stipe wires are your start circuit, black is ground.

Make sure to get a 6v relay. I had to hunt for awhile find any yamaha switch (qt50/mj50/whatever else) that was similar.

If anything, you can try pushing out the pins of the female connector and rearrange them in the correct order to match your new switch. May or may not work, but that saves you from have to splice.

Re: QT50 - Ignition/Starting

So I took that white plastic piece off that the key turns to make contact, and now I can't get it to go back how I had it. Battery is good, fuse is good, all the wires are good. If I start it, and put the plastic piece back on, it will kill it. Which it only does that when the contact hits the two gray wires that are soldered to one contact. I took the tumblers out and it will turn with no key, I just want it to make it look like you need a key. Any suggestions?

Re: QT50 - Ignition/Starting

Nevermind about the switch fellas, got it all figured out. Got it mounted back in the cluster and works as it should. Now just waiting for the flasher relay, then gotta find what's wrong with the tail/brake light, get a new headlight, tag it and we are road worthy. Thanks guys!

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Re: QT50 - Ignition/Starting

Have you tried checking the brake/tail light whilst revving the bike? I've had some be nearly dark at idle, and brighten up with some throttle. Probably a step you have taken, just a thought, though.

Re: QT50 - Ignition/Starting

Okay, got the new flasher. Right side still works, and it fires faster than with the old one. Left side still doesn't work, but the light on the cluster blinks instead. Anybody have any thoughts on that? Also I found nothing with the tail/brake. So if anyone has suggestions on that also, it would be appreciated.

Re: QT50 - Ignition/Starting

Sounds like a short in the wiring on the left side.

Re: QT50 - Ignition/Starting

I looked over the wires and didn't see anything unusual. I didn't dig real deep into it. I took the switch box off of the handle bars and everything looked good there.

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