I'm new to the forum and new to the BMW K100.. I have work on many older (70's) Honda's, Triumph's and BMW.

I found a BMW K100RS from 1985 with only 9800 km on the clock, wich I had to own!! I ran very well, but it only ran 10-11 km/liter. I pulled the plugs and they were black.

I have had the bike apart and change alot of parts (all the obvious):
- Air filter
- New plugs
- New oil
- New watertemp. sensor
- New themostat
- New fuel regulator
- New fuel and vaccum lines - plus new hose between the crankcase and air intake (small rubber hose with two bends)

But it is still runing VERY rich - I made a small video with it runing: https://www.dropbox.com/sh/jkanleimg3ce506/AAClfmFIl2eDsCZl-WHJeZXaa?dl=0

I'm going to check the fuel pressure - to be sure it is spot on, and if so the next thing I will check are the injectors.

Any other good ideas???

best regards

Thor

Welcome to the forum too. 9800km is very low.

I have the same problem at the moment with my 84 K100RT. Fuel was normally about 16km/litre and it changed and is doing about 11-12km/litre at times. I did not change any adjustments yet.

Welcome!

If the injectors are not leaking then I believe I would use deoxit on all electrical connections having to do with engine management.

If that doesn't help then check the AFM.

Welcome Thor from sunny Tasmania Australia



Great forum - lots of very knowledgeable people here. I am sure someone will give you a solution to the fuel issue

Cheers
Gary

Hello!

1.) 1985 has the old ignition coils, quit common that the are defect.
2.) have the Valves been adjusted?
3.) have you checked all rubber with break cleaner, spray on the left side, while the engine is running, if you hear changes, the rubber are done/cracked, it's a 1985 bike they should all be changed.
4.) after doing point 3.) and only than, they bike should be synchronized !

By the way, a speedo can be changed, I have K speedos with ZERO km/miles on it, or anything you like. 90% of all early speedos also been changed by BMW.
Your bike looks good so far, as I can see on the Video.

Measuring the break disk gives often a better km/miles reading.

Cheers and enjoy your bike

Hey guys..

Thank you for the warm welcome..

Chocolate - I know, but given the condition of the bike I think the km/miles are correct. I think the bike has been a garage bike, that was what the former owner told me.

I think I have loacated the fault. I tested the fuel rail pressure today and is was very high (more than 70 PSI). The fuel regulator is brand new, so I don't belive thats the problem (orig BMW).

Could it be a clog in the return line?? or what could cause this?

best regards

Thor

Hi Thor 
Welcome also from Denmark, 

I believe you said you changed All the fuel lines, OpenOffice the gas cap and have a look at the front left inside the tank, then presse the starter button There should be A big squirt of fuel, from the return line if not There is a non return valve that could be blocked

Sorry for the short reply,the family needed My attention, 
The non return valve, is a small Ball,placed in the stud where the return line connects, i believe the purpose is to keep pressure in the fuel rail. 

K-rider

Hey k-rider..

the tank I full of gas, so I think I will pull of the return line and try to see if fuel comes ouy when i hit the start button. if not, i will take off the tank, drain it and check all the pipes inside. I dont think my bike has a non return valve. They were removed on 1985 and up. 

/Thor

If you supply the VIN then we can tell you all about it.

thormeyer wrote:Hey k-rider..

the tank I full of gas, so I think I will pull of the return line and try to see if fuel comes ouy when i hit the start button. if not, i will take off the tank, drain it and check all the pipes inside. I dont think my bike has a non return valve. They were removed on 1985 and up. 

/Thor

Welcome along, quiet a few from Denmark here too. Put your bike's VIN Number in the signature line and it helps accuarcy of the advice when getting answers on your bike.