Odd Stalling Behavior

markjenn · 11-30-2001, 06:35 PM

I've had my bike (late-prod 99 bumblebee, 15K miles) stall twice in the last month. The first one I wrote off to sunspots and bad karma, but it did it again today, so I'm starting to be a little concerned.

Symptoms: Within 5-minutes of cold start, the bike just sputters and dies from idle, fairly abruptlly. You can crank to the cows come home, but it won't start - won't even fire. Cycle the ignition and it fires up and runs fine for the rest of the ride. Nothing else unusual.

Any ideas?

- Mark

Mrmerlin · 12-01-2001, 07:37 AM

Hi Bro , on the stalling look at the fuel vapor lines and see if they are piched........then make shure the valves are adjusted,then sync the throttle bodies , then make shure the idle is set after she warms up... if none of these cures the problem then it might be time for you to replace the fuel filter in the tank this is the hardest job to do so I saved it for last, while your in the tank make shure all the clamps are tight try to twist all the hose connections if any move replace the clamps with the screw type as they have a tendency to slide off from time to time.....Stan

markjenn · 12-01-2001, 09:37 AM

Thanks for suggestions Stan, all good stuff, but stuff I'd associate with symptoms of gradual degradation and difficulty in idling, rather than having the bike stall and then be impossible to restart without an ignition cycle. The fact you have to cycle the ignition implies some sort of electrical or electronically controlled fuel metering issue to me.

Ride safe,

- Mark

roger albert · 12-01-2001, 08:59 PM

Hi Mark,

I'd agree with your comments it must be electrical. Have you also tried toggling the kill switch (which among other things enables the fuel pump and ignition) or is it defitively narrowed down to a strict requirement of igntion cycling.

To narrow it down, i'd pull (and externally ground) a plug and see if you're getting spark in that condition. Since I don't see any sort of pressure accumulator in these systems (unlike most cars) then I suppose it's possible to get no restart due to no fuel when the pump shuts off when the motor dies. (most systems are set to shut off at least the pump, and many the ignition, when the motor stalls. Normally, the start button resets this sort of circuit. The question here is first whether the problem is fuel or spark, and why the interrupt.

Anyway, I'm really not sure, but if I was working on it, I'd definitely be looking to find out if I had spark after the stalls.

good luck
roger

markjenn · 12-01-2001, 09:19 PM

Good suggestions. Assuming it happens again, I'll see if it is kill switch or ignition switch related. If I'm not in a hurry, I'll just leave it dead and see what the spark situation is.

OTOH, it may vanish "like a fart in the wind" as the warden of Shawshank liked to say. A year ago I had a couple stutters followed by jumping out of 6th occur in one day, but I've driven 5K since without a single one.

- Mark

lennie · 12-02-2001, 12:48 AM

Mark,

I have a problem similar but not quite terminal.

My bike will sit and idle during normal commuting, and then all of a sudden at the worst possible time, (eg split a lane at a red light and as it is changing green) it dies. Mine starts ok but I get worried about being run over at the front of the queue.

Have not been able to sort it out as yet.

Regards,

Lennie