So from my last post I fitted new fuel injector seals and checked that they worked and that injectors fired and no blockages. Fresh petrol and bike started and sounded really surprisingly good. Smoked a bit at the start as expected but soon cleared up .
Helmet on and out for a test run . Going lovely for about a mile the I had to slow down for a turn off. Bike cut out and wouldn't start. hmmmmm.
Two guys stop in car and said hi I'm a mechanic whats up . So he gets out and clutch in barely any throttle and bike starts !!!!!! So he says do you mind if I ride it back up road to my house so I said go ahead, So he takes off and it sounds lovely and the minute he backs off it cuts out again. 
Anyone any idea whats going on before I start stripping it ?( Short history of bike . It lay up for four years , I got it and changes plugs ,oil ,battery ,petrol. Cleaned fuel injectors and it went lovely until this ).

Sadly there are many threads on this subject and many things that can be the cause of the problem. No one can really diagnose your particular problem but many will be along to make suggestions, and there will be loads of them.
Your bike is exactly the same as mine, even the colour. mine has the correct exhaust fitted whereas yours seems to be fitted with the older 8 valve exhaust, I wonder if that makes any difference to the bike with having an 8 valve 90 hp exhaust rather than the 16 valve 100 hp one.
You should never need throttle to start a K, but the lever on the left holds the throttle slightly open for cold weather starts.

BobT wrote:Sadly there are many threads on this subject and many things that can be the cause of the problem. No one can really diagnose your particular problem but many will be along to make suggestions, and there will be loads of them.
Your bike is exactly the same as mine, even the colour. mine has the correct exhaust fitted whereas yours seems to be fitted with the older 8 valve exhaust, I wonder if that makes any difference to the bike with having an 8 valve 90 hp exhaust rather than the 16 valve 100 hp one.
You should never need throttle to start a K, but the lever on the left holds the throttle slightly open for cold weather starts.

Thanks for that , Yes this is going to be a learning curve for sure and yes the guy that stopped to help me today started it with no throttle. I feel like it runs out of fuel thats the only way I can describe what happened but it has half a tank of fresh fuel. So I'm gonna have to find a faulty part possibly

Don't blame the exhaust.  I have the same setup on my K100RS 4V and it runs great. 

Do you have a screw adjustment on the front of your relay box just behind the throttle position sensor?

It controls the idle mixture and may be too lean.  You need to take a plug reading at idle and adjust for a slightly black electrode.  Turning anti-clockwise makes the mixture richer.  The screw has 10 turns from end to end.

.75 refers to the CO2 potentiometer the setting checks can be found below the sketch with pin numbers, see link .


http://www.k100.biz/pdf/FAQ/NT_consumo_by_Frank_Warner.pdf

Get yourself a digital multi meter to do the testing.
Write down all your settings before you make any, you can always get back to where you were.
Make one change at a time before testing.

Hope this helps.

Cheers

After getting the bike home I contacted the previous owner. So apparently he had an issue with the side stand cut out which stops the fuel pump ?
So anyone heard of this . Im gonna check it in the morning when I dry out .

Unless modified a K 16V will not start with the side stand down (disables fuel pump)

Here is a picture of the switch.



You can short the wires together, where the switch connector plugs into the loom, for test purposes

Ringfad wrote:Unless modified a K 16V will not start with the side stand down (disables fuel pump)

Here is a picture of the switch.



You can short the wires together, where the switch connector plugs into the loom, for test purposes

Thanks I think ill do that . Read so much about this issue seems to be multiple  causes .

Hi Peter, good to see you!

A simple check.....had the same on my 8 valve....connector to the petrol tank was dodgy, cutting the power to the fuel pump and then it cut out....and would restart again because some little movement would reconnect it for a moment.

Check back on what you disturbed doing the job, as in what connectors you opened, battery out? Motronic out? tank off? dodgy sidestand switch? disturb the ignition to loom connection under the tank?

But first check the side stand one mentioned above. Sounds a likely one and you need to be enjoying the K. Mine will have done 300 miles this week......glorious winter weather too.


Will we see you at Draperstown ABR weekend of 19 May? Camping weekend for some of us, even bought a new tent today......been 5 years since I bought a tent.!

92KK 84WW Olaf wrote:Hi Peter, good to see you!

A simple check.....had the same on my 8 valve....connector to the petrol tank was dodgy, cutting the power to the fuel pump and then it cut out....and would restart again because some little movement would reconnect it for a moment.

Check back on what you disturbed doing the job, as in what connectors you opened, battery out? Motronic out? tank off? dodgy sidestand switch? disturb the ignition to loom connection under the tank?

But first check the side stand one mentioned above. Sounds a likely one and you need to be enjoying the K. Mine will have done 300 miles this week......glorious winter weather too.


Will we see you at Draperstown ABR weekend of 19 May? Camping weekend for some of us, even bought a new tent today......been 5 years since I bought a tent.!

Cheers and yes your right , could be something I disturbed albeit I bought the bike after it lay up for a few years . But engine sounds fine and tight and rides smooth for a mile. Could be pushing it to Draperstown at this rate . Gonna do a complete check of the wiring over the weekend. Got the feeling theres more to it though .See how it goes.

Excellent idea to check the stand first.  With the early model muffler the sidestand does sit just a bit different from how it would with the oem stand.  Could be just enough to cut off the fuel pump.

The other probability is the Hall Effect sensor. It lives behind the T shaped cover at the front of the motor. When it gets hot it stops working and the bike just cuts out. Leave it for 10 mins to cool down and it'll go again like nothing was wrong. Repeat as often as you like. My RT did this last year. Changed the sensor and its been good ever since.

Something else you want to do is check the throttle position sensor.  Unlike the 8V engines, the 16V engines have the mixture determined by this sensor. 

The spec is for .375V at throttle closed.  To make it easy to check there is a test built into the Motronic control. 

To check the setting of the throttle position sensor, lift the seat.  There is a big heavy cable under the seat behind the battery.   About 5 inches from the big connector that is connected to the Motronic unit there will be a black 3 pin connector connected to 4 wires sticking out of the cable. 

The pins on the connector are numbered on the side of the connector.  Take the bare end of a wire and put into pin #3.  Connect the other end of the wire to ground.  Turn on the ignition, but don't start the engine.  The high temperature idiot light should be lit.  Make sure the "choke" is turned off.  Turn the throttle.  If the throttle sensor is adjusted correctly, as soon as the throttle is opened, the light will go out.  Closing the throttle will make the light come back on.

If the light is not showing properly you need to adjust the throttle sensor before you do anything else.

I told you that there were a million things it could be. 
If you follow all the posts so far and do everything that is mentioned, your bike will be in a thousand bits before you know it! 

Did you put a new fuel filter in.

BobT wrote:I told you that there were a million things it could be. 
If you follow all the posts so far and do everything that is mentioned, your bike will be in a thousand bits before you know it! 

The upside is with a little cleaning they're ready to take to the powdercoater.

BobT wrote:I told you that there were a million things it could be. 
If you follow all the posts so far and do everything that is mentioned, your bike will be in a thousand bits before you know it! 

Good advice Bob.  I guess he should just scrap the bike.  Being in a thousand bits will just facilitate parting it out.

So I have complexly checked al connections and all seem good . Came out this morning and bike started instantly . 
It won't idle and cuts out after a few minutes. Convinced this is not electrical and that it is something I the fuel supply. Gonna check throttle position sensor and maybe try adjusting idle screw.
Checked petrol tank again today and thought the fuel looked cloudy and not clear ?
Not sure if that means anything.
Ye know if it was a ordinary bike engine I would just clean carbs and adjust idle but this is not funny. Beginning to regret buying it .

Ive ordered a new fuel filter and some hose incase they are contaminated or blocked .

Peterk100rs wrote:Checked petrol tank again today and thought the fuel looked cloudy and not clear ?

As BobT has mentioned, there are many different causes of engine cut-out. An orderly approach is necessary to keep madness at bay. 

The fuel shouldn't look cloudy. You need to get a good look at what's happening in the tank. Ethanol is part of the fuel additive scheme in your neck of the woods. A K-bike idle for years with an ethanol gas mixture in the tank is likely to have its hoses and fuel pump vibration damper start to disintegrate which in turn will block fuel flow in many places. Siphon out the fuel, carefully remove the fuel cap assembly and its gasket, then look for debris. You'll be ready to install the fuel filter and hoses anyway.

Yeah I believe your right . Just spoke to guy who owned the bike and said he drove the bike everyday until it was put away with no issues. 
Im gonna empty out tank and remove it . Gonna take everything out and either replace or clean fuel pump if possible too. Its the only way to take it out of the problem. The petrol was clear when I put it in yesterday and its cloudy today so this has to be effecting the running I would say.

Cloudy fuel sounds like water contamination to me.  Ethanol additives attract water that can settle out in the low spots right where the fuel pump pickup is located.  It's a good idea to get that water out since it not only makes the engine run poorly, they can promote corrosion that causes leaks in the tank. 

You could disconnect the supply hose to the injector rail and power up the pump to pump a sample into a bottle.  Let the sample sit for an hour or so and the water will settle out at the bottom. 

Drain the rest of the tank and soak up any remaining fuel before refilling with fresh.  Water can damage the element in the fuel filter so you might want to replace that before the new fuel goes in.  Any steel shell filter will work if it has 8mm connections, no need to give an arm or leg to the BMW dealer to get one. 

It's also possible that there is some dirt that has been loosened and gotten into the injectors.  It is not a bad idea to add some Chevron Techron to the new fuel.  A bike that has sat for several years will have some varnish in the fuel system that takes a while to flush out.  Techron will help speed the flushing process.

Point-Seven-five wrote:Cloudy fuel sounds like water contamination to me.  Ethanol additives attract water that can settle out in the low spots right where the fuel pump pickup is located.  It's a good idea to get that water out since it not only makes the engine run poorly, they can promote corrosion that causes leaks in the tank. 

You could disconnect the supply hose to the injector rail and power up the pump to pump a sample into a bottle.  Let the sample sit for an hour or so and the water will settle out at the bottom. 

Drain the rest of the tank and soak up any remaining fuel before refilling with fresh.  Water can damage the element in the fuel filter so you might want to replace that before the new fuel goes in.  Any steel shell filter will work if it has 8mm connections, no need to give an arm or leg to the BMW dealer to get one. 

It's also possible that there is some dirt that has been loosened and gotten into the injectors.  It is not a bad idea to add some Chevron Techron to the new fuel.  A bike that has sat for several years will have some varnish in the fuel system that takes a while to flush out.  Techron will help speed the flushing process.

Yes I agree. As soon as filter and fuel lines arrive I will strip it all out and clean everything . Was going to use some sort of additive to help clear any other muck that may be in there.

I have a sister ship that is very similar except for color and having had the ABS removed.  I have about a year of tinkering and restoration invested.

When you get her running right you are going to like her a lot.  As I have said many times before, don't begrudge the TLC you are giving her.  Think of it as foreplay.

Point-Seven-five wrote:  As I have said many times before, don't begrudge the TLC you are giving her.  Think of it as foreplay.

And think of yourself as Optimus Prime, if that helps.

Peterk100rs wrote:Ya know if it was a ordinary bike engine I would just clean carbs and adjust idle but this is not funny. Beginning to regret buying it .

“...... There will be days when we lose faith.
Optimus Prime


Take a look in the tank with a torch. You should be able to see a bit of the pump and its mounting. It could be looking a bit messy. Typically the vibration damper goes to mush and coats the inside of your tank if its left too long. Order a new vibration damper and pump. EME or Motorworks for the mounting parts. You may also need a new pre-filter.
Other than just running the pump with some fresh fuel and maybe some carby cleaner to flush it out, it's not really serviceable. You can get a Chinese pump off ebay for around $100 if needed.

Hopefully its just the filter. (have you checked it's round the right way?)
Ryco Z200
SupaCheap SCF200
Valvoline VF6
Fram G4777
Its a pretty common filter and used in quite a few different cars including earlier toyotas

When I bought my first K-bike it had around 80ml of water in the tank. That can be due to bad cap gasket and/or blocked drain hole in the cap recess.

One of the first things I do when trouble shooting is to check the spark plugs. That will give you a bit of an idea about what's happening.

Cheers

Thanks for the info. New battery, new plugs , injectors taken out and clean ( and checked that they work )
Stripping tank and fuel lines today . Fitting new lines and filter.
Bike starts and runs but cuts out after a few minute . Doesn't matter if it's stationary or moving same thing happens .

So I come out the morning to strip out petrol tank and to my suprise the petrol is completely clear not cloudy . Really not understanding this .
So yesterday I started the bike and then looked in rank and fuel was cloudy , today I didn't start bike and fuel us clear ?

The water has probably settled out overnight. Give it a good stir with a clean stick and it will most likely change colour again.

You are making the mistake of looking into the tank when the engine is running, the bike was designed so that when the key is in the ignition and the engine is running you cannot open the tank. 
When the engine is running the FPR will dump fuel back into the tank and cause bubbles, small ones look like cloudy fuel. Shut the tank and run the engine as there is no need to have the tank open with the engine running.
You are causing yourself more grief by looking at things that do not need looking at.

No the engine wasn't running this morning. I just looked in the tank first thing as I was going yo strip it .

So I guess the fuel is going through filter and pump and some gets sent back to the tank . So possibly that hose is fractured or sucking in air , causing the cloudy petrol?

Peterk100rs wrote:So I guess the fuel is going through filter and pump and some gets sent back to the tank . So possibly that hose is fractured or sucking in air , causing the cloudy petrol?

No, I doubt it, again you are looking for things that aren't there. Why should anything be fractured?
If the engine is running then fuel does get pumped back to the tank and makes the fuel turbulent and swirling, it could look cloudy because that fuel going back into the tank may contain air bubbles and that would probably be completely normal. If the fuel looks fine before you start it and you can't see ant debris/water in there then shut the fuel tank and forget it.
What will happen now is everybody will open their tank and start their bike, something which is never normally done in the whole life of a bike, but everyone will now be trying to fix a problem that does not exist!

Peterk100rs wrote:So I guess the fuel is going through filter and pump and some gets sent back to the tank . So possibly that hose is fractured or sucking in air , causing the cloudy petrol?

Hi Peter,

What happens is that the fuel pump pumps the fuel from the tank at about 60 psi. This is reduced by the FPR fuel pressure regulator [buried behind the air box but accessible by removing the bottom half of the air box] to about 36psi and the balance goes back into the tank. You will always have fuel bubbling back into the tank. 

BUT occasionally if the fuel line inside that tank that's under pressure is damaged or loose you will get bubbling but no go because the fuel system is not getting pressure to operate and all the fuel is being madly pumped around inside the tank. There is a small length of flexible fuel hose inside the tank and if that's in trouble you will get everything working but no firing of the engine due to lack of fuel pressure.

Its not a complex system but its a good thing to get a good understanding of it, make troubleshooting easier.

Don't be tempted to throw money and new parts at it, can become frustrating and that's why we get so many Ks that have been off the road for years.

Running perfectly to cut out is more likely to be something electrical. Hall sensor mentioned, is worth running the test on that. I had to replace mine. But I also had an issue with the plug on the FICU under the seat causing an intermittent cut out on uneven surfaces. I also another time had an issue with the electrical plug that plugs into the fuel tank [front left on my 84K]. On the LT I had an issue with the unit up under the headstock.

That sounds nightmarish but being a regular on the forum they all sorted very easily and for very little money with he help from the guys here.

My money is on water in the fuel.

As Dai mentioned, the water in the tank settles out overnight.  When you start the engine the fuel coming back from the regulator stirs up the water to make the fuel in the tank look cloudy. 

As soon as enough water is stirred up it gets in the injectors and kills the engine.  Let the engine sit for a couple minutes and the water settles out so with a little cranking the injectors clear and the engine starts and the cycle begins again.

I have read that part of the problem with rubber parts in the fuel system is related to this water.  There is a bacteria that lives in a water/ethanol/gasoline mix that feeds on the plasticisers in the rubber, breaking it down.  If the water has been in there a while, there is a chance the vibration damper for the pump may be bad and need replacement.

If there is water in there and it gets to the injectors then it will go through them, the water will soon be gone unless someone is adding water to keep some in the tank.
The bacteria that you speak of grows in the layer between the water and fuel and is quite visible, I know this as in my past I have spent many a night shift cleaning it out of aircraft fuel tanks.

So I drained the new petrol out of the tank into a container , replaced fuel filter and hoses . Wiped the inside of the tank clean and sprayed some injector cleaner in them .
Came back after to lunch and this is what the fuel looks like. I would say thats water and contamination at the bottom. By the way the container is full. The rest is petrol on top . Hopefully this is my problem sorted. Tomorrow il get it back together and test it . Oh and its getting in through a damaged tank cap gasket.
Thanks to everyone who gave advice and help . Very much appreciated.
e

Funny one that.....when I got the parts for the rear main seal and clutch etc I ordered a new tank gasket.......

Make sure the hole is on the left side as you sit on the bike and run a check to make sure the pipe from that hole...it goes through the tank and comes out underneath....make sure it is draining water away.

Peter, when you put it back together, make sure the hinge on the tank lid is positioned facing the rear toward the seat.  Otherwise it will block the drain hole for the lid recess. 

BTW, I can't see the photo of your bottle.

Point-Seven-five wrote:Peter, when you put it back together, make sure the hinge on the tank lid is positioned facing the rear toward the seat.  Otherwise it will block the drain hole for the lid recess. 

BTW, I can't see the photo of your bottle.

Photo uploaded this time to last post

Water in fuel. Bottom is water and crap from the tank. Top is full of new petrol. I guess this is it !!!!!

That looks like a beer with a good head on it. says a lot for the K that it went at all.

92KK 84WW Olaf wrote:That looks like a beer with a good head on it. says a lot for the K that it went at all.

Well I'm not out of the woods yet . We will see how it goes after putting it all back together and some fresh fuel (again). Hopefully a good run will clear it out . Fingers crossed.

Yeah, that is more than enough water to ruin your day. 

Have you wiped down the inside of the tank?   How does it look in there?  Is the pump rubber in good shape?

Keeping the inside of a K tank water free can be difficult. I usually put about 100ml of mentholated spirit in the tank after I have been riding in the rain for any extended time. 100ml will absorb 150ml of water and let it pass through the system without any harm at all. Any more than 100ml will not be easily absorbed into a full tank of fuel.
It will pay to do that as there will be some droplets of water that were not got and they will settle right under the pump and the electrolysis will start to eat the alloy and eventually cause the dreaded fuel leak.

Also check the rubber vibration damper around the pump by running your finger on it. If you get any black bits rubbing off on your finger, then it needs replacing.

RicK G wrote:Keeping the inside of a K tank water free can be difficult. I usually put about 100ml of mentholated spirit in the tank after I have been riding in the rain for any extended time.

Is that the purple stuff that smells of mint? 

Dai wrote:

RicK G wrote:Keeping the inside of a K tank water free can be difficult. I usually put about 100ml of mentholated spirit in the tank after I have been riding in the rain for any extended time.

Is that the purple stuff that smells of mint? 

MINT Yuk mine tastes of Burbon

You blokes are sick puppies!

Yes I have wiped the inside of the tank checked the rubber and replaced the hoses . The only contamination I found was bits of hardened gasket , which I think fell in when I removed petrol cap . Tank looks in good nick with no rust . Rubber is fine and not coming apart .
Will find out later today How it goes .