Bike stalls dropping into first

[Ted]

Well, this one has me stumped: my '99 cuts out instantly when I shift into first gear. It only happens when I first start it up, never when it's on the road, or after sitting at a red light, (which is a good thing) but when I first start it up, or start it up after filling the tank, etc. Start the bike in neutral, clutch in, but as soon as I drop the shift lever it dies (yes, with the clutch in.)

I put dielectric grease on both the connectors, gave it a wee crimp, it still does cuts out. But not every time. If I unplug and then plug the connectors in, it fires right up.

Any thoughts?

[qcbaker]

This is gonna sound like a stupid question, but is your kickstand down? The bike has a safety switch that kills the engine if the kickstand is down and the bike is in gear. Either you're putting the bike in gear before putting the kickstand up, or that switch has failed.

[Ted]

Nope, kickstand is up, all ready to go. Both feet flat on the ground, lift the left one to the peg, drop the shifter down to first: cuts right out.

[Kilted1]

First thought is a minor vacuum leak causing it to stall when under load, like dropping into gear when it's cold, and maybe you're not leaving the choke on long enough. 

Second thought is, exactly which connectors are you tinkering with?  If un/re-plugging helps, then that may be the answer.

Third thought, seconding qcbaker, the kickstand switch is failing or failed.

Good luck and let us know how it turns out! 

[Watcher]

Does the bike want to "jump" when it happens?

I wonder if your clutch is extra sticky when it's cold and is, in effect, not disengaged completely even if you've got the clutch pulled all the way in.

What oil viscosity do you run?  When's the last time you did a proper 3-point clutch adjustment?


But then again:

If I unplug and then plug the connectors in, it fires right up.

Sounds like a simple electrical fault.  Likely suspect is the side-stand switch.  Hate to be the guy to recommend bypassing it, but I've had many bikes with either failed switches or switches bypassed by previous owners and never had a problem with any of them.  It's an autonomous part of my mounting procedure that I sweep off the side-stand, it's usually up before I even straighten the bars out.  I'm not particularly worried about leaving the side stand down by mistake.  Also, I like the idea that if the side-stand spring is lazy or weak you won't have the bike shut off from going over a large bump or something.

Either way, it's easy enough to test by disconnecting the plug and then using a makeshift shunt to connect it back up.  If the issue goes away when the wires are shunted, it's a bad switch.  Get a new one, problem solved.

[mr72]

There's also a side stand relay that could be bad. And about 8 ft of wiring.

[Ted]

To Kilted 1: It's not really under load, since the engine dies before I even let the clutch out. Also, it can do it after the bike is fully warmed up, like just after filling the tank up after a long ride. The connectors I'm referring to are in the picture (maybe I should check out that thread as well for possible solutions).

To Watcher: Bike doesn't jump, and it does it when warm or cold. I'm like you, side stand never down when I start the bike (force of habit from kick-starting). Oil viscosity is 10W40, if memory serves. I've never done a 3-point clutch adjustment. Never crossed my mind.

To mr72 and qcbaker: If it's an electrical problem somewhere between the side stand and the handlebars, I'll probably try to bypass rather than fix.

Thanks all.

[mr72]

To mr72 and qcbaker: If it's an electrical problem somewhere between the side stand and the handlebars, I'll probably try to bypass rather than fix.

Yeah, try it, and if it works, great. If not you may have to chase it up the chain. In other words, the switch may be OK, in which case jumpering won't help, but the wiring may be flaky between the switch and relay. Or the relay. Or the wiring on the other side of the relay, etc. etc.

Try the switch first.

[qcbaker]

Yeah, try it, and if it works, great. If not you may have to chase it up the chain. In other words, the switch may be OK, in which case jumpering won't help, but the wiring may be flaky between the switch and relay. Or the relay. Or the wiring on the other side of the relay, etc. etc.

Try the switch first.

+1 to this.

It really sounds to me like its something with the side stand switch, whether it be the switch itself, the relay, or some part of the wiring.