Hoping this won't tax too many grey cells.
Yesterday I went to my daughter's to bring my '89 K100LT home to my new workshop for a few jobs. Hadn't been run for about 2 months but started without any problems!
When starting to move off it did take a few seconds to get it going again but put that down to being well down reserve and seeing I was only going a couple of miles, I restarted and drove on.
Got home ok and decided to give it a wash before starting my few jobs. After I washed it, it wouldn't run on all four and eventually cut out. Put a gallon of fresh fuel in but now it won't run at all.
Pulled the plugs but no smell of fuel on them. Gave them a clean and they seem to getting a spark ok.
When I put the fresh fuel in after washing it the usual small amount of water fell into the tank and now I'm wondering if the water has built up in the tank and letting it run so low has allowed the pump to suck it up and blocked the pump/filter/injectors.
Is there a way to prevent this water getting into the tank after washing it?
What is the best way to purge any water from the system?

I don't know Bro. If it was my bike doing that, the first thing I'd do is listen for the fuel pump when I turn the key on. If it hums normally for that second or two when I first turn on the key then I would probably pull the fuel line and turn it over.....see if the fuel pump is pushing fuel to the injectors. If it's not then I would assume the fuel filter is plugged or the pump has gone south. Then I'd take the fuel filter off and try to start it without the filter, just to see if it starts. If it catches then you know your filters bad. If you don't get any action with the filter off then I'd pull the pump and check it out. I guess that's where I'd start if you know it's getting fire.

Other than that, check your breather intake and make sure no critters have made there way in while it sat for a couple of months and are blocking your airway with a big 'ol nest! lol

My dad always said "Boy, there's three things a motor needs to run.....fuel, fire and air. Check all of those first!"

Water can be sucked up by a suction line by targeting the globules in the bottom of the tank. Water in the filter blocks that, so no fuel gets through.

Check the pump is running and the injectors are receiving firing pulses. If both are OK it points to fuel not getting through and the filter is a likely candidate.

If water gets in have you checked the filler cap rubber washer is it the right way round to drain water that ends up in the recess?
Regards,
K-BIKE

On both my bikes that had been sitting for awhile the small hole that is the drain in the fuel neck was clogged and letting water sit there, still if the seal is good no water should have been able to get into the tank.

On my K100 the fuel pump does not run when the key is cycled to on, it only starts to run after the start button is pressed.

Hi Chrish,
You are absolutely right the early K's didn't run the fuel pump at ignition turn on they need a short push on the starter button after turn on to make the pump run for a few seconds so one can hear them.

On the later K's like the 1990's the pump runs when the key is turned on so it is a thing one gets used to listening for when turning the key on.

The fuel cap washer gets turned around sometimes when the fuel filter gets changed and it is worth checking it is still alligned, when I got mine it wasn't.

Once the filter is water contaminated it is time to change it as it inhibits fuel flow.
Regards,
K-BIKE

The fuel pump had died. I had started another thread on replacing it called 'Cheap fuel pump'.
Strangely enough, K-Bike, I discovered that the fuel cap washer on mine had been the wrong way round the whole time when replacing the pump and filter.
Drain now lined up.
Tried blowing through the old filter after I removed it and found that it took quite an effort. Worth changing on a regular basis.

You are so right about the filter, I suspect that is 90% of the reason that BMW quote the distance to replace the filter plus our tanks (motorcycle tanks) are very prone to condensation due to the cold air on the tank when it is low on fuel and has humid air drawn in from outside. I know our old Volvo 240 instruction manual advises in damp climates to keep the fuel tank topped up so as to reduce the air volume and hence the moisture. My pal has a Suzuki Intruder and his tank rusted out completely at the lowest point due to condensation. It finally failed when we were on a road trip together and we had been lent a garage at the motel for overnight, when we came down the smell of fuel was strong and there was a puddle under the bike. When he found the soft spot a gentle push of the finger broke the paint film which was all that was holding the rust together and a finger sized hole appeared.
Regards,
K-BIKE

I rode my bike a fair few K's today, some of it in heavy rain, until the tank was nearly empty. The low fuel light had only just come on. Upon filling it it topped off with 18 litres. I had stopped and re-started it several times throughout the ride with no troubles. The bike ran strongly all day. The fuel filter has less than two months on it. The fuel pump sometimes whines loudly but less than half the time, is my best guess. The temperature was less than 25c with some bright sun today.

Upon starting it and riding away from the servo I stopped a coupla kilometres up the road for a slash. When I walked back to the bike it cranked in a slightly offbeat manner and would not fire. I lifted the petrol cap and it was brimming. I hit the starter button again, the engine still would not fire and I could not hear the customary buzzing of the pump. I checked the condition of the fuses for good measure and not being able to read German proficiently I couldn't tell which one might have some connection to the pump. One of them was loose to the point of nearly falling out. I pressed it in and started the bike immediately - I could now hear the pump whirring.

At another fifteen minute stop down the track the bike again would not fire. I popped the petrol cap and removed and replaced the four-wire connector on the right hand side which clips to the ECU. It fired and ran all the way home, no worries. It re-started upon arriving home in my driveway. It started just now (cold) in the garage. The vent in the petrol cap surround is free of obstructions and I'd replaced the entire cap assembly a couple of months ago. This bike is a daily rider. I don't own or drive four wheels at all.

I will see how she goes in tomorrow's travels. I've read all of the various posts about 'no start' conditions and have a spare fuel pump relay under the seat if needed.

The pump might just be ready to give up the ghost, buy the farm, kick the bucket, slink of this mortal coil, push up daisies, kark it, bite the dust, cash in its chips, or have one foot on a banana peel and one foot in the grave.

I got the problem of a fuse creping out once. I fix it by inserting a piece of foam between the plastic cover and the fuses. The foam keeps a 'gentle' pressure on the fuses.
Few years ago, my brother drove into a big pot hole (big enough to that he blew the front tire and bent the rim). He never crashed the bike, but all the fuses got dislodged from their socket.

Here is the fuse and their function:

1(top)---> 7.5A - FI relay, Kill switch Stop light, Bulb monitoring, accessory socket
2 ---> 7.5A - Parking Light Bulb monitoring
3 ---> 15A - Flasher unit, clock
4 ---> 15A - Unused
5 ---> 15A - Alarm, lights
6 ---> 7.5A - FI relay Temperature unit, Fuel pump
7 ---> 15A - Load shed relay Flasher unit, horn relay, alarm socket

Ta for that, CF. I will have a pleasant day of yet more riding in the rain if last night's steady drumming on the roof is any indication. The high tech foam 'stay' is in place and extra travel time allowed for standing on the side of the motorway fixing (or attempting to fix) a minor mystery.

Two days worth of riding and no further dramas with the 'no start' issue. It may well have been that loose fuse. Some days the sun shines over us.

yay !!!!!
beutifull weather lately...nice cool nights ...and glorious days of mid twenties ......and some new tires on the old beast makes for some nice riding weather