KZ650 Dies mid ride?

Hi guys,

I just recently had my bike running for the first time. Over the weekend I did some minor things like change out the handlebar and install new signal lights/tail light. I went around the block a few times and then my bike suddenly died. There was a little juice left because my NEUTRAL light was on, but not enough to hear the starter attempt to get going. A few minutes later it completely died. I pushed it back home.

I was coming down a straight and was accelerating to about 40 kmph after a bend and when I came off the throttle, the bike backfired and then promptly died. One thing to note here is it took me a few tries with the starter button to get her turned over, so I was likely draining the battery quickly. It was probably close to not having enough juice to turn the motor over, but then it did.

Is my issue that I am staying within the rev range of 1k - 3.5k while the battery was already pretty low and this caused my system to not be charged fast enough? Does this make sense? Or is it possible that my regulator/rectifier needs replacing as I've read other people have done...

I'm a new rider so I was taking it pretty easy throughout my test ride and that's why I didn't really push it, but could this might mean I was never able to charge the system and that's why it died?

Anyhow, I am charging the battery now and I am planning to go around the block again tomorrow to see what happens. Any thoughts welcome.

Do you have a means of checking the voltage across the battery once you get it running after charging the battery? You need a volt or multimeter to do this. You should be getting a reading of about 13.5 volts at tickover.

The motorcycle needs a good fully charged battery to start & run right. After charging, it should be at least 12.6 VDC, but a good battery usually will be higher. After charging, you could do a high beam load test. Ignition switch ON, engine off, headlight high beam ON >> the voltage should drop to about 12.2 VDC. If it drops to around 11.85 VDC, the battery may need replacing. If it drops below 11 VDC, the battery is probably bad. These are the voltages I use. there may be a chart on the internet. I use a Ctek US 0.8 smart charger & test w a VC97 digital multimeter.

ps: if it's a wet cell battery, be sure to check the electrolyte levels. add distilled water as necessary.

I would expect a bad electrical connection somewhere. Wires like to come off at the ignition switch and the fuse holders often let go.

Letting off the throttle might have been enough to shift a harness etc just enough to stop making contact.

The 77 Kz650 charging system, when working properly, makes enough power to recharge a battery anywhere just off idle, and sometimes even at idle if the idle is a bit high.

Has the wiring been gone through on the bike?

loudhvx wrote: I would expect a bad electrical connection somewhere. Wires like to come off at the ignition switch and the fuse holders often let go.

Letting off the throttle might have been enough to shift a harness etc just enough to stop making contact.

The 77 Kz650 charging system, when working properly, makes enough power to recharge a battery anywhere just off idle, and sometimes even at idle if the idle is a bit high.

Has the wiring been gone through on the bike?

You were right, I had some funky wiring going to my handlebars, the right switches were shorting out. I redid wiring on both sides of the handlebar with new wire and quick connectors down to the frame and no electrical issues!

Thanks! Phew glad I didn't have to tinker with the charging system.

Thanks for the update. Nice job tracing that down. It's not easy to find the break.