Hello all - I was hoping that I had finally cured all of my K100 gremlins and indeed the bike has been running beautifully over the last few months. Recently however I have noticed that whilst riding, the engine will suddenly die for no apparent reason - as if I had mistakenly hit the kill switch (I hadn't) and then pick up and carry on again as if nothing had happened, very often doing another 100 miles or so before the same thing happens again. I have ruled out fuel as being the issue because the entire fueling system was refurbished not long ago when the bike was recommissioned after 14 months non running (see my other posts), fuel is circulating normally and a clear flow back to the tank can be seen. I have been using this bike regularly over the last month or so (glorious weather here in the UK) and thought that the issue had in fact resolved itself ! Went out for a local 40 mile ride yesterday and all was fine but as I arrived back at my garage the engine suddenly cut out once again. It restarted relatively easily and I parked up and didn't really worry too much. I went to use the bike today for a local charity ride and it started on the button, ran for a minute or two whilst I was putting helmet on etc. and then suddenly cut out - as if somebody had just turned the kill switch to "Off" ! I ended up taking the K1100 instead as I was running a tad late by now. When I got home from the ride I thought I'd take another look etc.- to me this seemed as if it must be something electrical so I checked all of the usual suspects (4 wire connector to fuel tank, ECU and earths and applied DeOxit in all the relevant areas as a mend all policy. However, the bike would not stay running for any length of time without cutting out as if I had hit the kill switch. All helpful suggestions would be welcomed at this point.

P.S. I have some spare (Motorworks) coil packs kicking around and that might perhaps be a logical place to go next but I am, as always open to any constructive advice as to what to do next.

Thanks in anticipation of your thoughts/suggestions

krambo

Have you cleaned any potential corrosion from the four-wire connector which runs up the right hand rear side of the petrol tank and just where it separates it is clipped to the ECU's plastic support and tooltray? It contains the fuel pump's power lead. Last year mine was cutting out intermittently, often leaving me stranded at the roadside for a few minutes, and then starting again as if for no reason. The male to female connectors were damaged and corroded and needed cleaning with Deoxit. I have had no issue like that since repairing the connectors.

I have had issue with that connector but don't rule out a fuel pump I had to replace one last October and all was sweet after that and I tested the old pump and it was very intermittent but then stopped playing up for a while and then started again. It was only about 18 months old at the time.

Guest in the House wrote:Have you cleaned any potential corrosion from the four-wire connector which runs up the right hand rear side of the petrol tank and just where it separates it is clipped to the ECU's plastic support and tooltray? It contains the fuel pump's power lead. Last year mine was cutting out intermittently, often leaving me stranded at the roadside for a few minutes, and then starting again as if for no reason. The male to female connectors were damaged and corroded and needed cleaning with Deoxit. I have had no issue like that since repairing the connectors.

Thanks for the rapid response GITH (TWB) - I will check that out on the morrow as it wasn't done in my diagnostics today. Will report back tomorrow evening with any observations/results etc.

Thanks again

krambo

Rick G wrote:I have had issue with that connector but don't rule out a fuel pump I had to replace one last October and all was sweet after that and I tested the old pump and it was very intermittent but then stopped playing up for a while and then started again. It was only about 18 months old at the time.

Fuel pump/filter/pipework etc. is all very recent Rick so most likely not the problem here - I will follow GITH (TWB)'s advice and see how we go - thanks for your input though

krambo wrote:Thanks for the rapid response GITH (TWB) - I will check that out on the morrow as it wasn't done in my diagnostics today. Will report back tomorrow evening with any observations/results etc.
Thanks again
krambo

No worries, mate. Back in 1999/2000 I had the opportunity of spending the Autumn and Winter season in rural Devon (could that be an oxymoron?). My redheaded English girlfriend at the time used to love to take drives further into the countryside. One day we found ourselves in Cornwall, and in fact in Launceston. I commented on the fact that here in OZ, down in Tassie, we have a Launceston as well and that the name probably came from Cornwall. I said it the way we would, as 'Lon-sess-tun'. She laughed and said it was pronounced 'Launce-tun'. She was a fair lass and I recall your town was under sunshine that day and equally fair. You can't go past the delish pasties on offer there either.

Guest in the House wrote:

krambo wrote:Thanks for the rapid response GITH (TWB) - I will check that out on the morrow as it wasn't done in my diagnostics today. Will report back tomorrow evening with any observations/results etc.
Thanks again
krambo

No worries, mate. Back in 1999/2000 I had the opportunity of spending the Autumn and Winter season in rural Devon (could that be an oxymoron?). My redheaded English girlfriend at the time used to love to take drives further into the countryside. One day we found ourselves in Cornwall, and in fact in Launceston. I commented on the fact that here in OZ, down in Tassie, we have a Launceston as well and that the name probably came from Cornwall. I said it the way we would, as 'Lon-sess-tun'. She laughed and said it was pronounced 'Launce-tun'. She was a fair lass and I recall your town was under sunshine that day and equally fair. You can't go past the delish pasties on offer there either.

Lol - the locals down here call it "Lanson" - then again they are Cornish (I have spent most of my life around Devon & Cornwall and regard myself as a south westerner but I was actually born in Cambridge)- it (Lanson) is the ancient capital of Cornwall (Kernow) and apparently also known as the "Gateway To Cornwall".

P.S. Your redheaded English girlfriend of the time was obviously quite posh - all the upper class folks that I know around here also pronounce it 'Launce-tun'

Have you checked the cable to the ignition switch?

Mike

mike d wrote:Have you checked the cable to the ignition switch?

Mike

It's on my "to do" list Mike

Guest in the House wrote:Have you cleaned any potential corrosion from the four-wire connector which runs up the right hand rear side of the petrol tank and just where it separates it is clipped to the ECU's plastic support and tooltray? It contains the fuel pump's power lead. Last year mine was cutting out intermittently, often leaving me stranded at the roadside for a few minutes, and then starting again as if for no reason. The male to female connectors were damaged and corroded and needed cleaning with Deoxit. I have had no issue like that since repairing the connectors.

Just a quick post to say that all is now well with the K100 - as I suspected GITH (TWB) was bang on the money again - I had forgotten about that pesky 4 pin connector to the right of the bike (despite having had issues with it in the past - how soon we forget). I cleaned and refettled it with the help of our favourite electrical cleaning spray and all is now well once again. Thanks again to all that responded to my post

Sorry to bring this issue up once again - after 2 months or so of running fine the same problem has once again reared it's ugly head. Obviously the first thing that I did was to revisit the 4 pin connector strapped to the frame, below and behind the fuel tank on the right hand side of the bike (whilst sitting on bike facing forwards). Once again I applied liberal quantities of De-Oxit and tried to make good this pesky connection. It seemed that once again the magical spray can had resolved the issue and all was well for 100 miles or so. Now however I am back to square one with this issue - the bike will start fine and run reliably for a while but I can feel now and again that it is like I have hit the kill switch whilst riding (I haven't) - the engine will die as if I have hit the kill switch but the engine will normally resume within a few seconds whilst riding at normal speed. It always gets me to where I am going and is more of a minor irritation than a real problem, however I am starting to distrust the bike and am avoiding dark roads at night or roads where I might not have a mobile phone signal to call for help if the bike cuts out and will not restart. All suggestions as to what might be the problem are welcomed. I think that, as a matter of course I will buy a new can of the "magic formula" and go right through every electrical connection on the bike once more - perhaps this should be an annual ritual ? All thoughts and suggestions will be welcomed (polite ones only please)

How much further did you clean the contacts? As you had to do the fuel tank connector I suspect all your electrical connections. You might want to start with the right handle switch gear ;-)
Further it might be that the female part of the fuel tank plug has too much free play. Try to squeeze the round receptors in a little bit with a very little screw driver (or toothpick) so the have a really tight contact on the pins?
Last (and hopefully not your problem) there have been instances of a wire break at the plug, so have a good look.

ReneZ wrote:Further it might be that the female part of the fuel tank plug has too much free play. Try to squeeze the round receptors in a little bit with a very little screw driver (or toothpick) so the have a really tight contact on the pins?

+1......since you allready have experienced problem with this connector........
a rather common problem.

Sounds exactly like the problem i had last Oct. Ignition switch, pull it, clean etc. Deoxit. Worked for me anyway. good luck.

krambo wrote:Obviously the first thing that I did was to revisit the 4 pin connector strapped to the frame, below and behind the fuel tank on the right hand side of the bike (whilst sitting on bike facing forwards).

And you are playing around with the correct connector or....?

On a -84. the connector to the fuel pump/level warning, should be at the front left corner of the tank.

Thanks for that Inge K - sometimes we forget the most obvious things ! This is a replacement tank with (as you rightly pointed out the four pin connector - front left under tank) I will revisit this connector and deoxit/make good once more. This forum keeps me sane sometimes

If it is a replacement tank you'll also want to check the spot where (and how) it was spliced into the original loom, as that normally wouldn't reach the right aft part of the tank.

ReneZ wrote:If it is a replacement tank you'll also want to check the spot where (and how) it was spliced into the original loom, as that normally wouldn't reach the right aft part of the tank.

All of the bike's wiring loom is original and as it left the factory - I simply fitted the replacement tank exactly as the old one was, ie the four pin connector to underside left front of tank. No other wiring was disturbed during the replacement and the bike has been running fine since I resolved the FPR problems a few months back. I will however recheck/make good the round four pin connector at front left and hopefully that combined with having made good the other connection at right rear and below tank (strapped to the frame), which I believe also carries power to the fuel pump etc. will put this issue to bed. It should be added however that when the engine cuts out the fuel pump can still be heard running. Thanks to all for advice once more

krambo wrote:that combined with having made good the other connection at right rear and below tank (strapped to the frame), which I believe also carries power to the fuel pump etc.

The only four pin connector in this area on a -84. ,would be the connector to the GPI switch.....which won`t affect fuel delivery, if it becomes less cooperative.

Inge K. wrote:

krambo wrote:that combined with having made good the other connection at right rear and below tank (strapped to the frame), which I believe also carries power to the fuel pump etc.

The only four pin connector in this area on a -84. ,would be the connector to the GPI switch.....which won`t affect fuel delivery, if it becomes less cooperative.

I reckon I have to be looking at the fuel tank connector then - 4 pin, round with a dimple in one edge. Hopefully I will find time tomorrow to have a good cleanup of this connection (weather not looking good here for weekend, so bike fettling time rather than bike riding time)

Well - I tightened and cleaned the connection shown in the post above and set out for a ride today. I thought that the problem was resolved as the bike ran flawlessly for around 30 miles or so. Then I felt a slight hesitation and engine tried to die just like before, however it soon picked up again and the same pattern repeated over the next 30 miles - die, pick up again, die, pick up again. I was never in any real doubt that I would get home but it is really starting to irk me now. I think maybe the next job will be to change the in tank fuel filter and see if that makes any difference, somehow I doubt it as this problem still feels like an electrical issue to me. It is like the fuel system loses its electrical pulse/signal every now and then but then recovers and carries on. Grrr - I hate intermittent faults almost as much as I hate electrics

krambo wrote:Well - I tightened and cleaned the connection shown in the post above and set out for a ride today. I thought that the problem was resolved as the bike ran flawlessly for around 30 miles or so. Then I felt a slight hesitation and engine tried to die just like before, however it soon picked up again and the same pattern repeated over the next 30 miles - die, pick up again, die, pick up again. I was never in any real doubt that I would get home but it is really starting to irk me now. I think maybe the next job will be to change the in tank fuel filter and see if that makes any difference, somehow I doubt it as this problem still feels like an electrical issue to me. It is like the fuel system loses its electrical pulse/signal every now and then but then recovers and carries on. Grrr - I hate intermittent faults almost as much as I hate electrics

AFter a tightening and cleaning that four pin plug , I usually fix to connector with peace of tape, to be shure it would be fixed. It works for years on my bike.

OK, note we are talking about the plug left/fwd of the tank and not right/rear.

(Edited as repeating earlier advice)

However you are now talking about loosing power whilst the pump is still running. Then the plug wouldn't be an issue. Is the ECU plug properly seated (it 'clicked'?)

Have followed all of the good advice above but am still getting this intermittent cutout problem whilst riding A point that might be relevant is that problem doesn't normally occur when the bike is still cold/ish. Once the engine is up to normal running temperature the problem kicks in once more. I am wondering at this point if the problem could possibly be temperature related and if so, where would I look for likely problem areas ? Thanks to all of those that have already replied to this post. I feel like I am almost there now, so any information about the above possibility would be warmly welcomed

removed

GARYSTIGER955i wrote:

krambo wrote:Have followed all of the good advice above but am still getting this intermittent cutout problem whilst riding A point that might be relevant is that problem doesn't normally occur when the bike is still cold/ish. Once the engine is up to normal running temperature the problem kicks in once more. I am wondering at this point if the problem could possibly be temperature related and if so, where would I look for likely problem areas ? Thanks to all of those that have already replied to this post. I feel like I am almost there now, so any information about the above possibility would be warmly welcomed

I have experienced excactly the same, but ive shrugged my shoulders at it.. in the 1800 miles ive done its happened 3 times and its been 2/3 hours into riding, the first time it happened, it were last week and it was very wet to say the least on the M1 about newport pagnell services from Sheffield around 6am it never did it again until end of last week, when I was on my way back from London, and it did it twice about 4pm, but the second time the death lastest about 2-3 seconds, on both occasions I were in the fast lane on M1, but after that I darnt venture into fast lane just in case, but Ive not really looked into it... but have certainly checked fuel pump connection, this was ok, and I know the rest of the connections are good because ive been through them and cleaned them with electrical cleaner, or as the aussies would say deoxit... I would suspect the fault may lie with the trigger/ wiring on the electronic ignition, as the fault is instant, not hesitant.

Sorry did you check hall sensor?

No.... the hall sensor is the electronic Ignition but just another name for it...

GARYSTIGER955i wrote:No.... the hall sensor is the electronic Ignition but just another name for it...

Maybe borrow hall from friend and try. As I understood from friend mechanic hall from earlier vw golf is the same

nino wrote:

GARYSTIGER955i wrote:No.... the hall sensor is the electronic Ignition but just another name for it...

Maybe borrow hall from friend and try. As I understood from friend mechanic hall from earlier vw golf is the same

I believe the hall sensor is slightly different on the vw, but does anyone want to elaborate on this...

Update

Hi mate
got the same gear display problem. When I had my swing arm off to do the spline lube I checked the gear position switch. It seems to be bakelite and the cover is all brittle and cracked. Same with my spare bike so I think we have reached the end of the lifespan now. The gears work perfectly just the message coming in from the switch. I doubt if it is related to your other problem.
New switch coming up for me.
RT

The gear indicator will be a seperate issue.
They do come apart but care is required and patience. Once apart clean it with a solvent and relube with a light coat of vaseline then clip it back together (if it won't clip back together feed it to the garbage bin) then seal with a silicone sealant or a polyeuthane glue like sika flex and leave sit to cure for a week or so. Test it by pluging it back in without installing and it should work.
If it is still cactus buy a new one and use the rest of the sika flex making it water proof.
I have managed to fix 2 of 3 that have gone faulty.

Well thats another to do then on the list of things to come........... These K's are hard work.. I suppose they keep you on your toes..

Getting back to the original problem posted by KRAMBO he said that when it cuts out, the fuel pump can be heard running so it is not the four pin plug or the electrical feed to the pump, that is intact and working OK or the pump would not be running. Are the injectors receiving power? It could be worth temporarily fitting a 12 Volt LED to one of the injectors. If/when the bike cuts out check to see if it is flashing when it is turning over on the starter. If you have access to a timing strobe or meter with a clamp on RPM measurement pop that onto one of the ignition leads to see if you have HV pulses coming through.
Regards,
K-BIKE

It might be worth checking out my post under the "other K Bricks" thread. I have exactly the same problem with my K75 but I suspect my problem is a bit more advanced than where yours is. About two or three years back the 75 started to just cut out on long motorway runs but would almost instantly re-start and continue to run. It was, as you say, almost as if someone had hit the engine stop button. After the first time it happened I assumed my gloved hand had let the throttle slip through it - it had that kind of feel to it. After three years this very intermittent fault has now progressed to the stage where it runs most of the time but occasionally, just as in your case, it will completely cut out and stall. The ignition lights would show but the engine would not turn over. When I first raised this on the K75 thread I was not really specific enough with the synptoms. I initially said that after stalling the engine would not re-start but what I should have said was that the starter would not even turn it over. Is this the case with your K100 or has it not progressed to this stage yet?

Once I had been a bit more explicit with the symptoms someone suggested checking the starter motor brushes and the earthing arrangements within the starter motor itself. As is well known the load shedding relay is grounded via the starter motor and if the earthing goes high resistance all sorts of weird and starnge things can happen that can't easily be identified or diagnosed. I have recently put my K100 on the road for the summer and have at last started to take a closer look at the 75's woes. Last night I replaced the whole starter motor's brush assembly which I bought new from Motorworks at a very reasonable price. It's too early to tell whether it has provided a cure but time will tell. I'll keep you updated.