Fuel problem?

[BlitzenGruv]

Rode the brick today. Got maybe half a mile when it coughed and wouldn't take throttle.
Walked home and returned with tools. Pulled the line off the fuel rail, turned the key and it flowed for a second. Only way to keep it flowing is to crank the starter. I noticed one small glob of water in the fuel I collected, so I presume that this is the problem.
How can I drain the tank without burning up the starter?

[Inge K.]

Easiest way would be to disconnect the starter (and isolate the wire end).

[Chaos]

try a bottle of Heet gas treatment.  I had the same problem (took a while to figure it out) and that solved it. 

[Laitch]

try a bottle of Heet gas treatment.  I had the same problem (took a while to figure it out) and that solved it.

Alcohol to the rescue! Ironic, isn't it.

[kennybobby]

You can drain the tank by pulling the line from the front end of the rail and pumping the fuel into a bucket.  To run the pump, make a jumper wire from the right side of fuse 4 to the left side of fuse 6.

[The Dude]

Alcohol to the rescue! Ironic, isn't it.

In moderation only...that's the water.

How can I drain the tank without burning up the starter?

Syphon!

[BlitzenGruv]

You can drain the tank by pulling the line from the front end of the rail and pumping the fuel into a bucket.  To run the pump, make a jumper wire from the right side of fuse 4 to the left side of fuse 6.

Now, THAT sounds like a plan, Thanks!
I shall do that, add some gas dry and a couple of gallons of fresh fuel.
I'm starting to miss the old Amal carbs, just open the drain plugs and the petcocks.  :eek:

[BlitzenGruv]

OK, so I pumped fuel out. Can't really see any water in what I collected. I added fresh fuel with gas dryer, still won't start. Actually it tries to start, just won't take throttle or stay running. Oddly enough, it won't even try with the "choke" fully on. If I crank it with the throttle fully open, then let off it tries harder to stay running but won't.
I have spark at the plugs, and they are wet when removed. All the fuses are good.
I thought I was through with working on bikes in parking lots when I bought this thing.

[Martin]

Remove the fuel pump fuse No 6 Kraffstoppe and see if it starts, if it does test the temperature switch,
Regards Martin.

[stokester]

I have spark at the plugs, and they are wet when removed. All the fuses are good.

If the plugs are wet with fuel, look toward ignition.

[BlitzenGruv]

Thanks for your responses.
Trailer reserved for Friday to get the bike home.
No time to chase wild geese. The K will sit until the BSA is back together and on the road.

[BlitzenGruv]

Remove the fuel pump fuse No 6 Kraffstoppe and see if it starts, if it does test the temperature switch,
Regards Martin.

And where might that switch be located?  Absolutely no mention of this in the factory manual.

[Martin]

It's sort of hard to see you need to remove the air intake snorkel. If you have small hands you might get to it otherwise you will have to remove the airbox.
Regards Martin.

[BlitzenGruv]

Thank you.
And what might a "normal" reading from the sensor be? I assume that it gives off an analog voltage somewhere.
Can I heat the thing to test it?

[Martin]

There are posts on how to test. I presume that by you wanting to test it that it started with the fuse removed. If it is flooded and you remove the fuse and it starts, as it start to die you can ram the fuse back in and keep it running. It helps if you have two people. Also have a look at this very handy'
The Motobrick Technicial Library / K-Bike Flow Chart Beginning When You Hit The Switch ~ author   Bert Vogel
Regards Martin.

[BlitzenGruv]

Thanks Martin
I went out today and tried to start the bike. Fuse out, fuse in, it didn't even cough. I downloaded the flow chart and will start at square one. I already have new intake O rings and bushings to install, good time to check out everything.

[Inge K.]

I downloaded the flow chart and will start at square one.

Be aware that it's for the 2V models, you have a 4V model......
all sensors, and the engine management system is different.

[Martin]

+1 Flow chart won't work with your bike. If the plugs are wet and it still won't fire with the fuel pump fuse removed it is not the temperature sensor. When you crank the bike over do you have spark.
Regards Martin.

[BlitzenGruv]

Plugs look wet and black. The last time the engine ran it was running rich.
I cleaned them and watched in the dark. All are sparking. I do wonder about the recommendation for resistor plugs when resistor wires are also used. With any other ignition system this is a definite No-No.
In any case, if the flow chart does not apply I am at a loss where to start. The Motronic system depends on too many things being correct to be reliable. I don't know why they couldn't program the computer to interpolate enough data to run with one faulty sensor while giving an error indication, as automobile systems do.
I'll check compression while the plugs are out. It's getting slow at work, maybe I'll get laid off and have time to chase wild geese.

[Martin]

I m not 100% sure but I believe a mates K100 RS just has resistor plugs fitted and not resistor leads. It doesn't make much sense having both. But in saying that a local BMW specialist  sold me resistor plugs for my 92 K75, I did try them could not see any benefit so I went back to normal plugs. Try looking up what plugs and leads suit your bike.
Regards Martin.

[Laitch]

Maybe your crankcase breather mod has a role in this. Checking the condition of that system is an option.

[BlitzenGruv]

Try looking up what plugs and leads suit your bike.

I did that before I bought the plugs. The leads are original as far as I know, and are plainly marked as 5K. PO had non-resistor plugs in place. I didn't really notice any difference when I put the new plugs in.

[BlitzenGruv]

Maybe your crankcase breather mod has a role in this. Checking the condition of that system is an option.

Always a possibility, but I thought that any leakage here would result in lean running.
While it's accessible I'll consider reverting to the stock breather hose. IF I can find one. All anybody seems to have available is for the 2-valve engine.

[Martin]

Is the Motronic system the same as the K1100. If it is type in BMW K100 Motronic fault finding you get a few sites on fault finding the Moronic System Motronic system.
Regards Martin.

[Inge K.]

It's the same generation (MA 2.1) as the early K11's (-93 year model).
I would have checked the air and water temp sensor and TPS, info you find in the K11ownersgroup forum.