Oilhead Tech Pages


Another Way to Start Your R1100RT With the Sidestand Down

Mick McKinnon  -  bmwmick@comcast.net


I recently made this modification to my '96 R1100RT.  It is a variation of the modification submitted by David E. B. Smith on the IBMWR Oilhead tech pages.

My version uses NO BMW parts (as long as you kept the rubber mounting donut from your charcoal cannister purge solenoid) so the cost will be the cost of your relay and a few pieces of wire/terminals.  This modification will allow you to start your R1100RT on the sidestand but will kill the engine if you shift out of neutral. What I have done is wired a common Bosch auxilliary light relay into the sidestand switch.  I pick the relay with the neutral switch and duplicate the sidestand switch function with the relay operating points. 


!!!!WARNING!!!!

Do NOT start your bike on the sidestand OR centerstand and walk away.  An RT running on the centerstand OR sidestand with no airflow WILL overheat in short order and might melt your fairing OR catch fire.

These instructions are provided as-is. This modification worked for me but there is no assurance it will work for you.  If you choose to perform this modification, you do so at your own risk.


You will need the following parts:

Here is a schematic of the modification:

Schematic of Modification




Before you start, it looks like this:

Wiring Harness

To modify the wiring harness:

1. Remove the left side fairing. You will find two connectors (pictured above) just inboard of the original purge solenoid for the charcoal cannister cable tied to the frame.. The sidestand connector has two wires, green/yellow and breen/red. The neutral switch connector also has two wires in it.  The brown/black is the 'switched' ground from the neutral switch and is used to light the neutral lamp.  Cut the cable ties and pull the connectors apart.

2. Prepare 4 lengths of  small wire (I used 22Ga Hi-Temp teflon insulated wire), 1 red 12" long, 2 blue 8" long and 1 brown 8" long.  Install female spade connectors on one end of each of these wires.  These connectors should fit the male terminals at the base of your relay.

3. Strip about 1/4" of insulation off of the sidestand switch wires separated by about 1/2".  Like this: 

Connectors connected

4. Solder the blue wires to these green/yellow green/red wires and insulate. The other end of the two blue wires should be connected to the relay.  One on pin 30 and one on pin 87.

5. Disassemble the neutral switch connector (I modified the switch side but you can do either side of the connector).  Route your new brown wire through the brown/black wire side of the connector and solder it to the existing terminal (I have the AMP pin removal tool so removing the terminal was easy).  The other end of this new brown wire is connected to pin 85 of your new relay. When you are done, the connector should look like this:

Plugged in relay

5. Route the new red wire up along the frame to the relay box.  I had a rubber grommet in the left side of my relay box from an earlier project and used that to pass the new red wire into the box.  Install a 'tap-a-fuse' to the rear side of fuse #1.  It is important that you use fuse #1 because it is NOT switched off during starting via the load shed relay.  Here is a shot of the relay box with the 'tap-a-fuse' in place:

Connectors tied to frame rail

6. I slid the new relay into the rubber donut that previously held the purge solenoid. I had to straighten the bracket just slightly to allow the new relay to fit flush with the inboard side: 

Extra connector to frame rail

7. I slid some 1" Heat-Shrink-Tubing(not shrink-wrap) over the relay base and the connectors just to keep them dry. All you have left to do is re-connect the connectors for the sidestand and neutral switches and cable tie them back into place under the frame rail:  

Relay position

8. I also covered my new wires with some 3/8" split wire loom sheathing.  Here is a picture of the finished product:

All Done

Now you can test your work.  Turn the ignition switch to RUN (do not start the engine yet) and shift to neutral.  The new relay should pick.  Shift out of neutral to either 1st or 2nd gear and the relay should drop.  Once you know the relay is being picked you can start the engine with the sidestand down and verify that the engine dies when you shift out of neutral.

That's it!  You now can start your R1100RT on the sidestand but you cannot forget to put the sidestand UP before riding off. 


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R-Tech pages maintained by: John Petty for the original author(s) and the Internet BMW Riders
Last Update: 09 September 2010