Pulse Generators?.......maybe?

[julimike54]

I'm trying to find the cause of a very short series of engine stopping on the '86 GL1200a. During a 5 day trip wandering NW Ark., on day 3 was riding through all the wonderful mountain roads and all of a sudden for less than a second the engine died (about 50mph, 5th gear going up hill out of curve) then refired & rode further. Over the next hour this repeated in varying lengths of time, the worst was long enough that I pulled in clutch, oil light lite and released clutch, it refired. Things I noticed when this occured were, most notable rpm dropped to zero even coasting in gear, every time I looked, no other electical symptoms appeared (ie lights stayed on, dash functioning, etc.). Once on a refire a loud pop eminated from the pipes. Most times the stoppage was less than a second & it allways refired. We stopped for a break (15 - 20 min.), looked over bike & saw nothing unusual. Wife talked to bike, haha. After that stop and for the rest of the 1100 mile trip it never did it again. I'm wondering if the key is the rpm drop to zero every time? Would that indicatre the pulse genrators stopped functioning & the cpu didn't know what to show on rpm and couldn't of course fire sparks?

Any ideas?
Mike

 

[dan filipi]

You have pulse generators on the front, I have read of them failing when hot.
Could this be early warning?

Could have a loose connection.
I'd go through all the wiring connections, unplug and clean/repair as needed.

 

[Omega Man]

What did your wife say to the bike, was it a threat? :?

~O~

 

[dan filipi]

I was going to comment on that too :smilie_happy:

Problem went away after her chat with the bike so maybe it's fixed.

 

[Tom_Charlton]

If everything else (lights, radio, blinkers, etc.) kept working, you have a bad connection in your ignition system. Since the tachometer and the ignition both stopped working, look for a connection that is common to the ignition and the tachometer.

If left alone, it will fail again. Check every connection from the battery to the ignition switch and the coils for looseness or corrosion. Clean as required and use di-electric grease to keep air away from the connections.

In my experience, when pulse generators fail, it is not intermittent. The PGs on my 86 Interstate would take you 4 miles and quit. No more, no less. I waited for them to cool and got within a block of the house before they quit again. I replaced them and have had no trouble since then.

 

[julimike54]

dan filipi » Today, 7:26 am[/url]":2yeu98e2]
You have pulse generators on the front, I have read of them failing when hot.
Could this be early warning?

Could have a loose connection.
I'd go through all the wiring connections, unplug and clean/repair as needed.

I was wondering about the early warning also.
I'm thinking about the connections also, going to be tough to know if I fixed it, with it not broke.

Omega Man » Today, 7:41 am[/url]":2yeu98e2]
What did your wife say to the bike, was it a threat? :?

~O~

I asked the same thing & she said it's between her & bike, Huh? :ahem: (and that's exactly what I did with the shades)
It has appeared to have "fixed it" (I'm waiting for the other shoe to drop, at the most inconvenient time)

PurpleGL1200I » Today, 8:19 am[/url]":2yeu98e2]
If everything else (lights, radio, blinkers, etc.) kept working, you have a bad connection in your ignition system. Since the tachometer and the ignition both stopped working, look for a connection that is common to the ignition and the tachometer.

If left alone, it will fail again. Check every connection from the battery to the ignition switch and the coils for looseness or corrosion. Clean as required and use di-electric grease to keep air away from the connections.

In my experience, when pulse generators fail, it is not intermittent. The PGs on my 86 Interstate would take you 4 miles and quit. No more, no less. I waited for them to cool and got within a block of the house before they quit again. I replaced them and have had no trouble since then.

It's not if everything else was working, everything was working. The others in our group I asked (at a stop light) to watch lights etc to see if they saw blinking on/off. When we stopped for the break nobody noticed anything blinking & everything I could see & hear never flickered either, just the RPM zero (when I could look down fast enough) & engine stop.

Isn't source of Ign & Tach the PGs? The other thing of course is the CPU is where the PGs go & Ign comes out, I think.

+1 on di-electric grease

The failure you describe is what I've heard also & this wasn't the failure mode I saw.

Has anyone rode along & flipped the Kill switch? I'm going to try that when I get home, see if RPM drops to zero right away. Maybe a dirty Kill switch?

Thanks for the info, start looking at wiring diagram & see what might be the problem.

 

[Denver]

My 84 standard acted very much the same when first purchased in 1998. :headscratch: Next time it happens wiggle the ignition key, which was my issue, new switch fixed the problem. :yes: But now have two keys for all the locks, unless each side is ground, one for each lock, but only works if properly inserted into the lock. :doh:

 

[Terry]

The worst kind of mechanical problem:

One that is inconsistent with symptoms that only occur occassionally.

Good luck duplicating it, resist the urge to just throw money and parts at it.

 

[Denver]

Terry has the idea!

 

[julimike54]

Ok did the ride & flip Kill switch, guess what RPM drops to zero, like now. More wiggling Kill switch replicated the symptoms, I'll bet the contacts are dirty. Time to take the switch apart. Any tricks or tips? Thank you Denver, you gave me the idea about wiggling!

 

[joedrum]

yes have magnifying glass LOL

 

[dan filipi]

Tip: take it slow and methodical. The parts are tiny.

 

[Denver]

Can't one spray electrical contact cleaner, with compressed air, then a clear water looking type silicon spray, followed by more air to clear excess? :headscratch:

 

[dan filipi]

Denver » 1 minute ago[/url]":3gqffqkm]
Can't one spray electrical contact cleaner, with compressed air, then a clear water looking type silicon spray, followed by more air to clear excess? :headscratch:

Worth a try. I did that at first then decided to open it up and it was still gummy.

 

[slabghost]

Old lube in these switches is really hard to just "wash" out. Just better to open and clean contacts and lube with dielectric grease.

 

[Denver]

Open it up first. Then try to spray, & lube.Sorry didn't mean to double post :blush:

 

[julimike54]

Just to follow up...last night took Kill switch apart & cleaned contacts & slightly stretched springs, reassembled. Now can wiggle switch all you want, no cutting out, woohoo!

 

[joedrum]

thats great like doing a heart transplant on a ant

 

[Denver]

Great work :good:

 

[julimike54]

It wasn't that terrible, took the top loose from the bottom, loosened the 3 screws holding wires, took switch inside & cleaned, etc. Needed three hands to assemble wires, thanks wife!