Greetings to all members!

Maybe someone could help me with advice over this trouble?

For over two months I have a problem with starting my 1989 K 100 LT. My buddy who helps me with maintaining the bike has tried everything - but the same problem repeats: the bike won't start, because too much fuel is coming to the cylinders, flooding them. When we take out the spark plugs, they are black and wet from gasoline.

We first tried with checking and cleaning the injectors - didn't help. A friend from Croatia, who's a magician for BMWs, and who installed a new pressure regulator on my bike few months ago (so THAT can't be the cause) sent me all possible spare parts that could have gone wrong - volume air flow sensor, fuel injection and ignition control units. We changed them one by one, in this order, and the problem still keeps repeating. For one day bike runs normally, but next morning it won't start

Each time I have to take out the spark plugs, clean them, take out fuel pump fuse and press the starter button in order to get rid of the excess fuel from the cylinders - only then bike starts and works normally. There IS a bit too much smoke coming out from exhaust, and when I stop at the traffic light one can smell the gasoline, so it looks the fuel/air mixture is too rich anyway.

Cheers,
Tarik

tarik this sounds like a injection control issue .
we have seen this many times and just lately found someone with an wet electronics board in the fi controller (rare)
likely 2 possible locations for this type of fault
the connector at the FI controller (under the seat )
the temp sensor ( behind the radiator on the water stub riser ) feeds 1> the injection control computer under the seat 2> the fan relay under the tank in the electrical box ...it is a double sensor in one unit
the connections to this sensor ...can become corroded at the pins on the sensor ....and the sensor threads to the water stub .
the connector to the sensor is the same as an injector electrical connection

to test the sensor measure pin 10 on the injection controller connection and earth .
at 10 degrees c it should measure about 4000 ohms

the operation of this device is as the temperature warms the fuel injection leans off

if this connector or sensor is faulty it will flood the bike consistently .....so a good clean of the connector pins is advised
there have been many posts about this same issue
try the "search" feature key words "temp sensor"

hope this helps

charlie99 wrote:tarik this sounds like a injection control issue .
we have seen this many times and just lately found someone with an wet electronics board in the fi controller (rare)
likely 2 possible locations for this type of fault
the connector at the FI controller (under the seat )
the temp sensor ( behind the radiator on the water stub riser ) feeds 1> the injection control computer under the seat 2> the fan relay under the tank in the electrical box ...it is a double sensor in one unit
the connections to this sensor ...can become corroded at the pins on the sensor ....and the sensor threads to the water stub .
the connector to the sensor is the same as an injector electrical connection

to test the sensor measure pin 10 on the injection controller connection and earth .
at 10 degrees c it should measure about 4000 ohms

the operation of this device is as the temperature warms the fuel injection leans off

if this connector or sensor is faulty it will flood the bike consistently .....so a good clean of the connector pins is advised
there have been many posts about this same issue
try the "search" feature key words "temp sensor"

hope this helps

Thanks - I hope too it will help! The temp sensor had been changed in summer 2012, so although we knew it's one of the "usual suspects" in this case, we did not pay much attention to it - guessing that if it was touched so recently, contacts must also be quite clean. But I do ride my bike also in the winter months, when there is a lot of salt on the roads around here - and THAT leads to corrosion