BMW K1100 LT poor starting problem

[Big_Arthur]

I have a 98 K1100LT with a starting problem. It will not fire at all with the choke on or accelerator opened. It will only fire on no. 1 and 2 cylinders for a few beats then stop. I then have to repeat this for about 7 or 8 times before no. 4 kicks in and then sometimes only when aided by keeping the starter going. It then stops when the accelerator is opened. When no. 3 kicks in eventually it will tick over but still unevenly for a short while, then runs evenly and only then can I accelerate. For the rest of the day it will run well and start ok. But the next morning it will be the same.

It has new plugs, new leads, can hear the pump, plugs the right colour, tappets checked, Wynn’s system cleaner put in tank. The symptoms rule out coils and hall effect sensor. I bought the bike with 16,500 miles on it. It now has 124,780. I have serviced it myself and it runs well apart from this starting problems. Can anybody help?

[Mitch9128]

This sounds exactly the same problem i have had previously on Bandits, it's how i knew the valve clearances needed doing, have you done them?

Doh, read it properly, yes you have. It's got to be something related to a cold engine though methinks.

[BB]

Snowy? :-?

[kn]

Try this page it's full of information. http://hrsbstaff.ednet.ns.ca/bvogel/K100/download/efi-web%20page/K100%20troubleshooting%20Starting.pdf
or http://www.ibmwr.org/ktech/cold-run-problems.shtml

From reading the above and other stuff on this forum http://www.ibmwr.org it would point to the Water temperature sensor not working and telling the computer that you have a hot engine not a cold one.



I have a 98 K1100LT with a starting problem. It will not fire at all with the choke on or accelerator opened. It will only fire on no. 1 and 2 cylinders for a few beats then stop. I then have to repeat this for about 7 or 8 times before no. 4 kicks in and then sometimes only when aided by keeping the starter going. It then stops when the accelerator is opened. When no. 3 kicks in eventually it will tick over but still unevenly for a short while, then runs evenly and only then can I accelerate. For the rest of the day it will run well and start ok. But the next morning it will be the same.

It has new plugs, new leads, can hear the pump, plugs the right colour, tappets checked, Wynn’s system cleaner put in tank. The symptoms rule out coils and hall effect sensor. I bought the bike with 16,500 miles on it. It now has 124,780. I have serviced it myself and it runs well apart from this starting problems. Can anybody help?

[Snowy]

When did you last change the fuel filter?

Best website for everything K11 wise:

www.k11og.org

[njl]

If it had been a carb bike i was thinking float bowl valves letting the motor flood overnight, but it isn't, so it wont be!

[470four]

Try this page it's full of information. http://hrsbstaff.ednet.ns.ca/bvogel/K100/download/efi-web%20page/K100%20troubleshooting%20Starting.pdf
or http://www.ibmwr.org/ktech/cold-run-problems.shtml

From reading the above and other stuff on this forum http://www.ibmwr.org it would point to the Water temperature sensor not working and telling the computer that you have a hot engine not a cold one.



I have a 98 K1100LT with a starting problem. It will not fire at all with the choke on or accelerator opened. It will only fire on no. 1 and 2 cylinders for a few beats then stop. I then have to repeat this for about 7 or 8 times before no. 4 kicks in and then sometimes only when aided by keeping the starter going. It then stops when the accelerator is opened. When no. 3 kicks in eventually it will tick over but still unevenly for a short while, then runs evenly and only then can I accelerate. For the rest of the day it will run well and start ok. But the next morning it will be the same.

It has new plugs, new leads, can hear the pump, plugs the right colour, tappets checked, Wynn’s system cleaner put in tank. The symptoms rule out coils and hall effect sensor. I bought the bike with 16,500 miles on it. It now has 124,780. I have serviced it myself and it runs well apart from this starting problems. Can anybody help?



Would be relevent? Sounds to be running far too rich, hence wont start on choke etc? When did you last change the air filter?

[Jon_W]

I'd agree with 470 that it sounds like runing rich. Suspect a sticking float in the carb.

The other one i have had is a broken choke linkage between the carbs.

[Snowy]

I have the BMW manual at home and will dig out the part number for the temperature sensor which lives underneath the water pump at the front of the engine There are two brass bolts there, the front one from memory is the drain for the pump, the one behind is the sensor which outputs the temperature to the motronic ecu. This one will also drain from the radiator side of the coolant system.

There's no "choke" as its fuel injection - the lever on the LH side is purely throttle advance.

The hall effect sensor would cut the engine if its hot not cold so it won't be that. Have you looked at the plugs straight after it won't fire up and before it does run properly?

I notice you are now on the K11 forum - had any feedback yet?

[470four]

Snowy - by "throttle advance" do you mean like a throttle preloader so it will tick over 'hands off' so-to-speak?

many years back a friend of mine had terrible problems with her Z650 after its Winter layup - it would start without choke, then die when it got hot?!

After Much Bafflement we decided to have a look at the carbs... in the airbox, taking up much of the top of the filter was a now-empty mice nest... :D

[Snowy]

Snowy - by "throttle advance" do you mean like a throttle preloader so it will tick over 'hands off' so-to-speak?

many years back a friend of mine had terrible problems with her Z650 after its Winter layup - it would start without choke, then die when it got hot?!

After Much Bafflement we decided to have a look at the carbs... in the airbox, taking up much of the top of the filter was a now-empty mice nest... :D



Yeah the cable goes direct to the fuel rail and will just raise the idle speed. If the cable has broken or is out of adjustment it could lead to difficult cold starts as the lever is in the advance position but in reality there's nothing working. You need to remove the left hand fairing on the LT and left bulkhead to get to it. You are looking for a cable leading to a locknut and adjuster just below the injector for No.1 cylinder.

While your in there check the connector to the throttle sensor - squarish box to the RH side of the injector rail.

You can also check the air temperature sensor which sits towards the rear of the airbox - there's a multiplug which connects to it at the back of the box.

Mind you, it looks like Big Arthur is away at the moment ;D

[Davehsw]

I knew there would be another LT owner out there somewhere...

[Big_Arthur]

Further to my starting problems only when cold. I met a biker who recommended a specialist at Chesterfield (Redline Motorcyles) who said it sounded like a fuel problem probably caused by supermarket fuel. So suggested I put Wynns Petrol System Cleaner in the tank and in the morning prime the petrol pump a number of times and it worked! It fired up like it used to, but the next morning it was same again! The morning after I checked the plugs before I turned it over, bone dry, checked for sparks – all ok. Put plugs back in, didn’t start. Took plugs back out, still dry. Checked fuel up to injector rail – ok. Spun engine over a few times, put plugs back in and it fired up straight away. Any ideas???

[Snowy]

What is confusing me is that the bike is running fine when warm. Typically this would rule out problems with the fuel pump, fuel filter, injectors etc. as well as the electrics and coils. And it rev's and pulls OK up to a reasonably high rev say 6-7K? Short of ideas on this one.

I would certainly check the multiplug connector from the fuel pump (4 pin). I had intermittent running issues with mine that turned out to be a poor connection here. It maybe that with the engine running the vibration is making the connections less intermittent or inconsequential? Same would go for the motronic connector under the seat - these can cause intermittent issues as well. The sidestand cutout switch can also get bad contacts making the engine think the sidestand is down but that (from memory as I disconnected mine) would disable the starter. Might be worth shorting it out to check but I would have thought you would have tried that one already.

Does the throttle advance (Choke) actually work - checked with the engine running does it increase/decrease revs as normal?

Is the battery healthy? K11's are prone to problems if the battery's not good. Have you checked voltage across the battery, engine off and on? 12.8V and over 14V is what you will be looking for.

Does the gear indicator work properly i.e it is reading neutral? If not, and the clutch cut out switch is inoperative the bike won't start as it thinks its in gear.

You say you changed the plug leads? Did you go OEM or third party with these and were they made for the K bikes?

[kn]

This one is a bit of a puzzle, hard to find a problem without the bike in front of you.
Have you done a compression test on the engine first thing and when cold?
Have you had your valves cleaned recently?

[Big_Arthur]

I thank everybody for their help and advice regarding the poor starting of my K1100LT,after many trials and tribulations I found the cause,whilst staying at Eastbourn it wouldnt even turn over so I called the AA who quickly diagnosed a duff battery which was only a few months old,got me started and followed him to a local backstreet garage who then fetched quality honda battery and fitted it,all problems solved! The cause,I had been sold a battery that wasnt powerfull enough in the first place,although I had specified make and model,so I took it back and got my money back but no apology for all the time and money it had cost me by them supplying the wrong battery.
Big Arthur

[BB]

Good to hear you are sorted! [smiley=thumbsup.gif]

BB

[Big_Arthur]

after riding for about 20-30 miles it suddenly cuts out! So after checking out the possible causes it would seem to be a faulty starter/kill switch.anyone know how to bypass it?

[Snowy]

after riding for about 20-30 miles it suddenly cuts out! So after checking out the possible causes it would seem to be a faulty starter/kill switch.anyone know how to bypass it?

You have checked all the usual suspects right? Sidestand switch, fuel pump connector, motronic multi connector under the seat? Never heard of the kill/starter switch failing before on the bricks.

[Big_Arthur]

this "cutting out"has been a problem for about three years now,sometimes going for a week or two and no problem then cutting out two or three times on the same trip,it would stop,wouldnt start again untill after about one minute,it would turn over but not fire up.
but now I find that if I switch the kill switch off and back on straightaway it continues running!This I tried after seeing this same problem on another website after he had frustratingly tried everything and found in the end it was a faulty kill switch!
Prior to this I have,bypassed sidestand kill switch,cleaned and checked all electrical connections under the tank,checked the fuel system,had the hair drier on the hall effect sensor,local BMW agents computor coudnt find anything wrong,removed Metza alarm so I am pretty sure its the hanlebar kill switch,so without the expense of replacing it I would just like to bypass it!

[NiteW4tcher]

immobiliser system installed?

[Snowy]

this "cutting out"has been a problem for about three years now,sometimes going for a week or two and no problem then cutting out two or three times on the same trip,it would stop,wouldnt start again untill after about one minute,it would turn over but not fire up.
but now I find that if I switch the kill switch off and back on straightaway it continues running!This I tried after seeing this same problem on another website after he had frustratingly tried everything and found in the end it was a faulty kill switch!
Prior to this I have,bypassed sidestand kill switch,cleaned and checked all electrical connections under the tank,checked the fuel system,had the hair drier on the hall effect sensor,local BMW agents computor coudnt find anything wrong,removed Metza alarm so I am pretty sure its the hanlebar kill switch,so without the expense of replacing it I would just like to bypass it!

Well, I guess you will have to work out the right wires then - here's a wiring diagram for a '94 RS which should be the same as yours.

http://www.skene.org/k1100/wiring/