Hi, title says it all. My K75 has been having intermittent issues and now has decided to be dead. Testing described below was with power on and cranking the engine. The starter does work correctly. Checked the power to the fuel pump at the connector just outside the tank. No power. Just to confirm believe this was the Yellow and brown lines. Though none of the lines showed power. Checked that there was no spark by two methods. 1.) pulled the spark plug connected the spark line and grounded the side of the spark plug, then cranked the engine. 2.)use of a timing light. Hooked the timing light over #3 spark wire and cranked the engine while pressing on the timing light's switch. Both methods indicated no spark.

So I've been going through Bert's diagnostic flow chart but haven't seen what would cause both the fuel pump and spark plug to malfunction.

Any suggestions?

best regards
JJefferies

P.S. I've been assuming that Bert's notes on K100 also apply to the K75.

Check all the ground points,1 under the tank and the one on the transmission. make sure the ICU plug is in tight and also the ECU plug.

RicK G wrote:Check all the ground points,1 under the tank and the one on the transmission. make sure the ICU plug is in tight and also the ECU plug.

Ground points yes. ECU and ICU. ECU is the box under the tank up by the steering fork. The box under the tool kit is what you refer to as the ICU?

The fuel injection control unit is under the seat. The ignition control unit is forward under the tank.

Absence of power to both fuel pump AND spark is telling. Usually its one of the 2. 

Is everything else working ok?

Kill switch fail can cause this. Also check you have either neutral light or clutch pulled in [switch can and does go faulty].

But first check the ICU and FICU connectors as said. Clean all the connections. Also, the fuel pump only works if the start button is pressed or if the engine is running.

Ok, thanks guys. I took the ground wires off, wire brushed the bolt, the area around it and the 5 wire ends, pulled the connectors for the ECU and ICU and sprayed them with cleaner and re-inserted. With the tank off I thought to try the starter and see if I had a spark. I have an electronic timing light that you clamp over the spark plug wires which would show if there was any spark. Engine fired right up even without the gas tank. Must have had some residual fuel. Shut it down and spent an hour or so putting everything back together. Took it outside and tried again. Fired up and ran satisfactorily. Makes me wonder if the loose connection was the gremlin I've been chasing.

thanks again.
J.

Good job

With every service I check all connectors and earthlines, to prevent these kinds of bugs.

First thing I look at when I have a problem like this is fuses and connections. 9 out of 10 times that's it even on my low tech bikes

yamaguzzi wrote:First thing I look at when I have a problem like this is fuses and connections. 9 out of 10 times that's it even on my low tech bikes

Its the place to start. Service and deep polishing can include this same routine and prevents a lot of problems.

92KK 84WW Olaf wrote:Its the place to start. Service and deep polishing can include this same routine and prevents a lot of problems.

+1

I recall reading somewhere(possibly in the BMW rider's manual) that a good cleaning on a regular basis results in a better running, more reliable bike because it forces you to look closely at the condition of your machine.  Having gotten into the habit back in my misspent youth when I was competing in enduros and reliability trials, I know it works because I've found several potential problems with my street bikes over the years.