'94 R1100RSL - GS Intake tubes

Good Memorial Day Afternoon !

My R1100RSL was produced in August of '93 and now has 44K miles. It has a Staintune exhaust and Ohlins shocks.
Recently, I've been lurking around the GS intake tube discussions on this site and several others and finally decided to try it out.

The tubes were installed yesterday and there's probably a bit more torque at mid-range but it doesn't make your heart all fluttery...
as noted by many others. However, there is a noticeably nice "honk" at mid range and part throttle! Also there's a lot of back firing
on deceleration which goes away if you turn on the choke??! Mixture too lean because of the GS tubes and Staintune exhaust?

It did this before the tubes were installed which I attributed to the Staintune exhaust but it's much more often and louder now.
I've checked for air leaks in the exhaust and intake and they are not leaking. The carb balance is a bit off but I'll adjust them tomorrow.

The attached image show the fuse box and images I've seen show a pink coding plug. As you can see there is no coding plug at all in
that position for this bike??!! Early production?

I ordered the GS Cat Code Plug 61 36 8 366 625 per the IBMWR Oilhead write-up before I learned there was no place to install it on this bike.

I'd love to keep the GS tubes and eliminate the back firing.

Your thoughts and comments would be appreciated.

‘94 r1100rs

I have a ‘94 R1100RS and went thru all this over 20 years ago. I added the GS intake tubes, found out the early RS was mapped only for the RS no changing of the different color coded map plugs. Added the Staintune exhaust system and got the bad idling small backfired and funky idling. Zeroing out the Throttle bodies kinda helped, but still not good. Found the Dobreck EFI Electronic Fuel Injection Controller. Got the unit for 1100s had a buddy of mine who’s a top BMW tech Install it then dialed it in. Perfect. Added the Ohlen shocks, big lids to the bags, RT rack and top case, more stuff. Nice touring package. Good luck with your project.

Indeed the early R1100RS bikes did not use a Cat Code Plug. As the first Oilhead bikes they were hardwired. The cat code plug innovation simply added a jumper socket to connect to various of the pins on the Motronic ECU which altered the mapping for various models in different national markets. This allowed the use of a single main wiring harness for several different models which could be tailored to each model ECU by using the CAT Code Plug which was just a jumper connecting different contacts in varying ways.

PGlaves said:

Indeed the early R1100RS bikes did not use a Cat Code Plug. As the first Oilhead bikes they were hardwired. The cat code plug innovation simply added a jumper socket to connect to various of the pins on the Motronic ECU which altered the mapping for various models in different national markets. This allowed the use of a single main wiring harness for several different models which could be tailored to each model ECU by using the CAT Code Plug which was just a jumper connecting different contacts in varying ways.

Click to expand...

What Paul said. :

Hey ! Many thanks!! Looks like I'll be returning the cat code plug I ordered.