Cause of too much fuel?

[Paul_F]

After the (very far away) BMW dealership twice repaired my non-starting problem by installing new plugs, I took the bike to a small local Honda dealer who has diagnosed the problem as being a rich mixture of fuel. Apparently the computer thinks that the engine needs too much fuel. Apparently the injectors should be receiving about 30%, not a 90% mixture. This dealership is now waiting word from another beemer mechanic to tell which part to replace on my ' 87K100RT.

Any suggestions what is causing such a high fuel ratio?

As an aside, I am very miffed that the big dealership replaced the plugs and it ran fine for 400 kilometres or so until the plugs burned out each time. As well, the local dealership has not been terribly sterllar with their servicing. If anyone in southwestern Ontario has a dealer or mechanic that does excellent servicing of their "Brick", please forward their address and name.

[GregFeeler]

After the (very far away) BMW dealership twice repaired my non-starting problem by installing new plugs, I took the bike to a small local Honda dealer who has diagnosed the problem as being a rich mixture of fuel. Apparently the computer thinks that the engine needs too much fuel. Apparently the injectors should be receiving about 30%, not a 90% mixture. This dealership is now waiting word from another beemer mechanic to tell which part to replace on my ' 87K100RT.

Any suggestions what is causing such a high fuel ratio?

As an aside, I am very miffed that the big dealership replaced the plugs and it ran fine for 400 kilometres or so until the plugs burned out each time. As well, the local dealership has not been terribly sterllar with their servicing. If anyone in southwestern Ontario has a dealer or mechanic that does excellent servicing of their "Brick", please forward their address and name.

Most likely you have either a dirty connection in the FI electronics somewhere, or a bad engine temperature sensor - maybe a bad pressure regulator. Testing the FI pressure should take them just a minute. Next, I'd take a chance it's the engine temperature sensor (which is also the fan switch) and test the voltage at cold and hot against book specs. If it's not working (or the plug-on wiring harness contacts are dirty) the engine will continue to run rich after it's warmed up. If that checks perfectly, then pull the tank and carefully clean ALL the connections: fuel injection controller (under the seat), ignition control unit (under the front of the tank), and all the plugs for the engine sensors.

[Dick]

Just curious, have you measured the fuel pressure in the system?

I had a rich running condition on my 92 K75s and it was a result of a return line being pinched between the tank and the fairing.