Hi
Recently purchased my 1985 K100RT.
Great bike. 
I had a R65RT years ago and really wanted a K100RT and finally got it 2 weeks ago.

Absolutely great bike. very happy with it.
Has the usual problems i.e. no fuel warning light but i have a fuel gauge coming and hope to find which wire to connect it to on here.
Still trying to find how to fill up the coolant as when it runs there are air bubbles going in to the expansion bottle and when cooling the coolant travels back. Sounds like a sealing problem but i have a manual on its way so i will soon find that out.

Thank you

Hi, and welcome to the madhouse   .

Sorry to say so......but your model doesn't have a level sensor for a fuel gauge,
unless it's a late -85.
If you have the connector for the wires under the left front corner of the tank,
or a single mounting screw at the rear end of the tank...you ain't got a level sensor.

Hi Worzel and welcome to the forum. We have more members around Peterborough too so keep your eyes open.

If you go to the home page there is a very good section on what to do if you have just bought a K bike.

On the coolant, if it is travelling back from the expansion bottle to the cooling system as it cools the sealing may not be a problem. Make sure the expansion bottle is topped up to the max line when cold and that should be it. The radiator fill cap is under the petrol tank and the tank must be lifted a little and slid backwards to access it. At 1985 you should check your fuel pipes, preferably replace them as they are under pressure all the time due to the fuel injection system and they perish. When you go at the tank they are likely to crack and leak. BMW line is cheap, but if you put them back a bit longer you can slide the tank and also raise it without having to disconnect them. This means it is much easier to access the radiator cap if you need [its on the right as you sit on the bike] and the electric box [relays are all in it, its under the back of the tank]. My RT is 1984, your tank is probably  held in place by a bolted plate at the rear of the tank, visible when you open the seat. If not then you have the later tank which is held in place by two poppers [like on the side panels] and clips which can be tricky to remove with the result that most leave them off.

There are wiring diagrams on the forum, you need to talk to Crazy Frog for access. Check out threads for the fuel gauge fitting too, others have been there before you.

Did you go for a Clymer manual?

When you get a bit more adventurous think about a trip over this way. Looks like we already have two takers for a trip to Northern Ireland in September. You have a nice route from Peterborough up to Holyhead and across to Dublin........especially if you take the straight line route across Wales...

Seems like Inge K has more information on this. So you gotta open the seat and check.

I am not sure about the feasibility of the gauge. My RT has the early tank and my LT has the later tank and the electrical connections are all very different suggesting its quite a task.

I haven't bothered with the idea of a gauge, content to know when the warning lights come on, I now know my 7 l light flashes at about 11 litres used, continuous on at about 14 used, 4L red continuous on at about 16-17 used. My rule of thumb planning fuel stops is about 10 miles per litre. What I don't know is the useable tank capacity. I ran the LT dry from full and it took 19 litres. The remaining fuel in the tank wasn't being picked up. Only a trial will give you that one.

92KK K100LT 193214 wrote: There are wiring diagrams on the forum, you need to talk to Crazy Frog for access....

The wiring diagrams you find at the portal.

Inge

Thanks for that. I haven't used the wiring diagrams as I relied on the Clymer manual.

Olaf.

The OEM manual you find here.

some great info to start me off.

the manual is a haynes.

Hopefully i do have the correct tank but will need check.

Thanks all