Topic: CB650 Starting Issues

[Goldbug]

Please read the entire post before making suggestions.

The basics:

1) Neutral Light On (plus tried to jumper the neutral/clutch switch)
2) Starter button shuts the headlight but the solenoid does not click
3) Jumpering the starter terminals engages the starter motor (but the bike will not start)

When I first got the bike the seller demonstrated to me that it started multiple times. Got the bike over to my dad's and the next time I tried to start it the button did nothing. Charged the battery and the button still did nothing.

Fast forward about a year. Decided to try and get her going one afternoon.

I replaced the battery with the TruGel from 500. The bike started. I shut it off. A few minutes later the bike would not start. Later the bike started and I rode it around. I replaced the inverted Elubmans with Euro Cafe bars and the bike has not started since.

What I've replaced:

1) The ignition key switch
2) The solenoid

Here's what I KNOW:

1) The starter works
2) The battery is good
3) Something happens when I push the starter button because the headlight shuts off (why is this?)
4) The solenoid and ignition switch are probably not the issue
5) The clutch/neutral safety switches are not the issue
6) Whatever the problem is, it WAS intermittent at one point (and may still be)

[cavi]

this may be a dumb comment but I am not too familiar with these bikes yet, but by any chance is there a kickstand kill switch that will not let you start the bike with the kickstand down?

[Goldbug]

There is no kickstand kill switch according to the wiring diagrams I've seen but I did try to start it off the kickstand just incase. That is where I'm at: trying stuff I know it can't be.

[fmctm1sw]

this may be a dumb comment but I am not too familiar with these bikes yet, but by any chance is there a kickstand kill switch that will not let you start the bike with the kickstand down?

No, not unless someone has wired one in for some reason.  And not a dumb comment, I picked up an old Suzuki dual sport bike years ago that kicked my @$$ until I figured out there was a switch there....

[fmctm1sw]

3) Something happens when I push the starter button because the headlight shuts off (why is this?)

That's by design.  It's so the battery doesn't have to power the starter and headlight when starting.

[Goldbug]

Do you know the mechanism by which that works? I don't see anything in the wiring diagram where the lights would be interrupted by the starter button. I could see the light dimming if the starter engaged and drew significant current but my solenoid doesn't even click.

[onepieceatatime]

Do you know the mechanism by which that works? I don't see anything in the wiring diagram where the lights would be interrupted by the starter button. I could see the light dimming if the starter engaged and drew significant current but my solenoid doesn't even click.

The starter switch is circled in red. As it shows, when the switch is free, the headlight (blue/white wire) is connected to power (black/red wire). When the button is pushed, it disconnects that and connects another power (black wire) to the solenoid (I cant tell if it is orange or brown/yellow wire).
I think the 1979 is wired the same way. It is the starter switch and associated wiring I would start troubleshooting.

[Goldbug]

Missed that one. So it's possible the button could still work in free mode but not in pushed mode. The button was the next thing I was going to look at.

I put a multimeter on the red/yellow wire at the solenoid and didn't get anything. I think it's either that wire or the button mechanism. I think it is less likely to be before the button.

[fmctm1sw]

This post is a good read: 
http://forums.sohc4.net/index.php?topic=49551.msg852059#msg852059

Look where he talks about the hard wired switch.  It's for a 550 I think but the design may be similar.

[w1sa]

When you press the starter button (with ignition switched on), you should get 12V at the red/yellow terminal at the starter solenoid......every time......otherwise, your switch contacts/terminals/grounds might need cleaning/refurbishing.

[Hush]

The clubman bars you replaced the old one's with, are they coated/black by any chance?
Have seen this happen a few times before when bars are swapped out and the starter button requires a good earth, the coating/paint prevents this and you get no start.
You could easily test this by using a battery jumper cable and providing a really good earth to that part of the bars.
Apart from that you seem to have done all the right things...try swearing at it, both my 650's went better the more I cussed them.

[cb650]

How about the clutch and neutral safety switch's?

[Goldbug]

Bars are chrome, same as the old ones.
Not either of the safety switches, already tried bypassing them.

[w1sa]

Then you should check the Starter Switch internals............particularly the black to red/yellow contacts.....make sure the contacts/wires are secure and clean.........check voltage is arriving at the black wire side and passing to the red/yellow terminal at the solenoid when you push the button.