Help please with BMW R1100 RS fault

[methamon]

Please can anyone help disgnose a fault with my BWM R1100RS 1994

Symptoms are:

Intermittent fault when opening the throttle from closed position (ie after changing gear). There is a short time delay before there is a distinct "kick" from the engine almost as if one of the butterflies in a "carburretor" is springing open.

Appologies if i am using incorrect terminology. I am aware that it is fuel injected. The throttle cables are free and I am pretty sure the butterflies are opening smoothly and in unison. I have run injector cleaner through it. I have cleaned the tank out. It has a new fuel filter & air filter. BMW approved dealer was unable to diagnose the problem despite having it in to check over twice. They tell me the valve & ignition timing are correct.

Can anyone assist as other than this irritating (and worst of all intermittent) fault it is a wonderfull beast.

Thank you

[bikesnumbnuts]

My advice is to get is serviced with another dealer , and if the fault is still there , you can tell them that it was running perfect before you had it serviced and they,ll have to sort it out.
The hall sensor could be the problem (which is where the signal is picked up for the ignition , situated behind the front engine cover).

regards bikenumbnuts (K1200 LT)

[BMWphreak]

Please can anyone help disgnose a fault with my BWM R1100RS 1994

Symptoms are:

Intermittent fault when opening the throttle from closed position (ie after changing gear). There is a short time delay before there is a distinct "kick" from the engine almost as if one of the butterflies in a "carburretor" is springing open.

Appologies if i am using incorrect terminology. I am aware that it is fuel injected. The throttle cables are free and I am pretty sure the butterflies are opening smoothly and in unison. I have run injector cleaner through it. I have cleaned the tank out. It has a new fuel filter & air filter. BMW approved dealer was unable to diagnose the problem despite having it in to check over twice. They tell me the valve & ignition timing are correct.

Can anyone assist as other than this irritating (and worst of all intermittent) fault it is a wonderfull beast.

Thank you


Well, it certainly does seem that it is fuel related. Take off the air tubes connected to the throttle bodies and inspect the TBs with a flashlight. Look for smooth operation and cleanliness. Have you or the dealer done a throttle body sync? Can you tell if it is both cylinders or just one that "kicks"?

[methamon]

My advice is to get is serviced with another dealer , and if the fault is still there , you can tell them that it was running perfect before you had it serviced and they,ll have to sort it out.
The hall sensor could be the problem (which is where the signal is picked up for the ignition , situated behind the front engine cover).

regards bikenumbnuts (K1200 LT)

Thank you for the advice! With regard to the Hall effect sensor and knowing nothing about how they work other than I think to trigger the spark, what can go wrong with them? Are they solid state?

Thanks

[methamon]

Well, it certainly does seem that it is fuel related. Take off the air tubes connected to the throttle bodies and inspect the TBs with a flashlight. Look for smooth operation and cleanliness. Have you or the dealer done a throttle body sync? Can you tell if it is both cylinders or just one that "kicks"?

Thanks for the reply. First I will inspect the inside of the throttle bodies and operation as you suggest. The dealer did synchronise both carbs, The fault was there prior to this and remains now. I can't tell if it is one or both cylinders that is affected as it happens when I am riding the bike following an upward gear change and re-opening the throttle.

Regards

[travelingman]

Does it make a difference if the motor is cold or hot ? When my halls sensor went out it faltered mostly when the engine was warm . There is a procedure for checking them one of the guys on here might be able to walk you through it or direct you to a site that explains it . But another thing to
try move the choke toward the closed position in small increments an try it.
That might help determine if its fuel starvation , did the dealer check the fuel
pressure ? Just food for thought good luck you will really enjoy the machine
when you get it sorted out .

[Steve_]

The throttle body boxer models are prone to wear where the shaft goes through the alloy housing ,because the butterfly is a precision fit in the throttle body any missalignment will cause sticking and uneven response flat spots poor uneven idling etc.

Fix is either replace with new or have a carburetor repair specialist rebush the throttle spindle bore,this could also be done by an acomplished machinist or even a good home machinist such as found building some of those amazing working model trains