K11 Owners Group

[Grunter]

I have had a couple of irritating problems involving the motor temporarily cutting out. One seems to have been down to a corroded ignition cable at the end that plugs into the coil. The problem only showed itself at small throttle openings and showed itself as a misfire. That has been cured by cleaning up the corrosion on both the coil and lead.

Now it has started to cut out when I am slowing down say to a road junction where I would have to change gear, the engine will cut out. It doesn't happen every time, which is one of the problems because that makes it difficult to diagnose. It doesn't matter if I break hard or gently. It makes no difference if the motor is hot or cold.

Hard acceleration does not induce this problem, only when slowing down in any gear. I have been on a club ride when it happened after 30 miles or so and then after a stop for coffee, the following 160 or so did not provoke the fault even with a lot of gear changes.

It always starts again immediately when I press the button and will then run at a steady 1000rpm without hesitation or irregularity - until the next time which can be several stops later or never again that day.

The plugs have been used for around 8000 miles and the colour around the electrode is just as it should be - light grey. The fuel consumption is well up to what I have been used to getting before the problem became apparent at around 55-58miles per UK gallon.

If it was electrical I am almost certain that the fault would be there all the time, There are no external leaks from the fuel pipes, at least I cannot smell escaping fuel, so I am thinking of dirty injectors - anyone else agree?
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1997 K1100LT
1994 R1100RS

[Scott_Anderson]

Which bike are you dealing with.
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Ride safe.



1995 K1100LT 0302044
1997 R1100RT ZC62149
2017 FLHTK Ultra Limited
Garmin StreetPilot 2820
Garmin Zumo 550
Garmin Zumo XT
"One who does not ask questions is ashamed to learn" Danish proverb
1997 K1100LT 0302488(R.I.P.)

[Grunter]

Sorry I should have said, - my K1100LT
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1997 K1100LT
1994 R1100RS

[Scott_Anderson]

I'd suggest taking some electrical contact cleaner/de-oxidizer and clean all of the plug connectors you can get at, including the motronic under the seat.

If you can get some of the spray into the kill switch and work it, as well as the ignition switch.

Disconnect and clean all the ground connections. Under the fuel tank, at the starter, and battery.

Check the starter brushes and clean out any excess carbon dust.

Check the side stand micro switch, it likes to collect moisture and can cause problems.

That will make for a good beginning.
_________________
Ride safe.



1995 K1100LT 0302044
1997 R1100RT ZC62149
2017 FLHTK Ultra Limited
Garmin StreetPilot 2820
Garmin Zumo 550
Garmin Zumo XT
"One who does not ask questions is ashamed to learn" Danish proverb
1997 K1100LT 0302488(R.I.P.)

[N41EF]

Remember the throttle position sender also has a function that cuts out the fuel injection at greater than 2500 with a fully closed throttle. Your position switch could be out of adjustment, dirty, or have a dirty connector.

And as Scott said, side stand switch, motronic connector and the grounds as well.

A plug wire, bad coil, or coil connection should act up all the time not just on deceleration.
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2014 R1200RT Water Cooled
2001 R1100S Light
1993 K1100LT. Nissan Ice Blue.(Gone)

[Mike d]

[Inge K.]

[Mike d]

Cheers Inge!

Mike

[Grunter]

I can confirm that after the recent interim service the exhaust valve clearances are absolutely spot on, midway between the smallest and highest measurments.

Also after when I had the inital misfire all 4 plug leads were checked and apart from one of the cables there was no defect, all the others were clean and uncorroded.

I am going to try another set of plugs - the ones that I replaced (Same make/grade) to see if I have a plug that is causing a problem - they are not unknown to break down under all sorts of conditions.

I am also going to question the condition of the flexible air tubes from the air box to the inlets. That might be a bit of a fiddle, there is not much room to allow an inspection. There is a way to check by spraying the tubes with something like WD40 and if there is a leak the engine note will change.

Ah well, onward and upward.
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1997 K1100LT
1994 R1100RS

[Grunter]

I can confirm that after the recent interim service the exhaust valve clearances are absolutely spot on, midway between the smallest and highest measurments.

Also after when I had the inital misfire all 4 plug leads were checked and apart from one of the cables there was no defect, all the others were clean and uncorroded.

I am going to try another set of plugs - the ones that I replaced (Same make/grade) to see if I have a plug that is causing a problem - they are not unknown to break down under all sorts of conditions.

I am also going to question the condition of the flexible air tubes from the air box to the inlets. That might be a bit of a fiddle, there is not much room to allow an inspection. There is a way to check whilst the engine is running, by spraying the tubes with something like WD40 and if there is a leak the engine note will change.

Ah well, onward and upward.
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1997 K1100LT
1994 R1100RS

[whyoldbill]

[Grunter]

I am not sure that being flamable has anything to do with it. It was explained to me tht the introduction of WD40 temporarily stopped any air leaks and this is what causes the engine note to change as the mixture is richened slightly.

Too cold and wet this side of the pond this weekend, with snow threatened so it will have to wait for better weather. I don't care too much for wind blown icy rain! javascript:emoticon('')
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1997 K1100LT
1994 R1100RS

[Grunter]

I accumulated all different ideas of what may be the problem and set to work to see if I could spot what was wrong. I started by checking all the places where I could possibly have an air leak (This seemed to be the most likely cause.) To be short I didn't find anything except the fuel pipe back to the tank via the pressure relief valve was not tightly fastened but not loose enough enough to leak.

I started the motor and allowed it to warm up before blipping the throttle. It was then I noticed that the brake light was on permenantly and found the front brake light switch was faulty. I replaced it with a known good spare and it was as if the bike had a new lease of life. The idle speed increased slightly and the pick up was cleaner

I went for a ride and after 30 or so miles and there was not one time the cutting out happened, despite trying to deliberately provoke the fault

I still have no idea what was wrong, but I seem to have fixed it. (or it fixed itself) Does anyone know if the brake light circuit is somewhere connected to the ignition circuit?
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1997 K1100LT
1994 R1100RS

[Al.]

I was thinking fuel filter.
Behaves peculiarly when filter is dodgy

[John Clauss]

[Grunter]

Thanks to all who passed on their tips. I have no idea how this was cured but it all points to the brake light problem. Now sorted, again thanks.
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1997 K1100LT
1994 R1100RS

[acftfliehr]

If this cut out situation happens again, check your ignition switch, I had the same issue on a K100, and was troubleshooting this for some time... as I would do something and the bike would run great for a few months... then the problem would reappear, sometimes att he most pucker factor moments... ie on freeways with no shoulders..

I did this and this was the fix.... Note, some say to put a lube on the contacts, however on the K100 site, run by the folks down under have stated to not do this as this contributes to arcing of the contacts...

http://www.eilenberger.net/K75S/IgnitionSwitch/