I have just been given the above bike. (poor condiction and fairing removed). Before spending any money I want to see it run. I have cranked it over and have concluded the fuel pump is not running when starter pressed. Could any one please tell me if I can conect power to the pump from the 4 wire tank connecter just to see if the pump runs, if so what color wires to +ve and ne-.

Hi and welcome.

I would be inclined to remove the pump from the tank, quite an easy job, and find out what nasties are lurking in there.

Gives you a chance to check the filter and test the pump externally.

As we don't know if your bike is an early K or a later one, it's a bit difficult to help you.
On the early K100, the color of the wires is brown and green-white. The under tank electrical connector is known to have some problems.
It would have been easy for you to find the color of the wires here
If the bike has not been used for years, I agree with Phil. You should drain the tank, clean it, replace the fuel filter and check if the pump is manually free to turn. Then you should try to power it. The pump is cool down by the fuel. Just try it once outside the tank.
If it's working, reassemble everything and start to troubleshoot the electrical.

Thnaks both. I will post my findings when I have removed the pump.

Have removed pump and the black rubber around the pump is like jelly, so I guess some will have got in the pump. If there is no other suggestion I will open the pump(saw an artical somewhere) and clear it out.

This was expected. The tank has certainly be filled with gas containing ethanol.
Here are the steps to open the fuel pump

get the pump out and submerged in a bucket, change the contacts around, this should make the pump run in reverse. Place filter in correct direction and let the pump run for a while and see in it cleans.

THe pump was completely seized up. I have stripped and rebuilt the pump. The pump now runs when I touch the starter button, however fuel sprays from around the edges of the pump.

Not letting that put me of I held the starter button in and low and behold the engine sprang into life. I bit of white smoke but thats probably ok.

So whats to do and is it worth it ?

Put all the fairing back togeter (if the bits are all there)
New Fuel pump
Repair or new water pump (the original problem was over heating, the impellar nut was broken)
new front oil seals
complete new seat

If this is done then I will have a tattry K100 , any thoughts welcolme

Thanks for all the help so far

Simple answer to "If this is done then I will have a tattry K100 , any thoughts welcome"...turn it into a rat bike!

Paint everything black. Never wash it again. No-one's going to steal it!

That's what I'd do if I had a "not so perfect" K100 as a second bike.

If the bike was free you must get it running and use it ,even for the sake of cheap motoring , if not why dont you pass it on to someone else who would benifit from having cheap transport . .

Had the same problem with my fuel pump and the rubber surround. Blocked the filter but pump was ok. All the parts you mention would be easily available on ebay without spending too much. I would do what blakey suggests and put it back on the road.

O.K, I have now fixed the fuel pump, so I decided to run the engine for a while to make sure it was ok.

Bad new,a lot of steam in the exhaust, so I guess the means a head gasket problem at best.

Time to give up.

Shame

not time to give up . . get the spanners out and start learning

time to get the money out and buy one that works

Wrap it up in bubble wrap, stick on some stamps and post it to me!

In my opinion, I would give it a good go to try and get it up and running.
You've fixed the fuel pump. That's a step forward.
Do a compression test. That's step two.
Take it from there to see what's next.

Don't let another one of these fine bikes slip into oblivion!

spend the money on your bike and get it going instead of spending it on something that will have issues of its own . . also if you fix your own one it will be the devil you know . . your probably 80% of the way getting it roaded allready.motobins gaskit and seal kit £65+vat + your labour costs