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jstevie

New member
Greetings Forum Friends,
I purchased my 97 R1100RT 2nd hand, and it was fitted with a Ztech low back-pressure exhaust. O2 sensor and catalytic converter were removed. As I am getting into long distance riding, the loud exhaust has become a nuisance. I've found a few second hand stock exhausts on ebay, and wonder what, other than exchanging the two systems, I need to do. Should I change engine timing? Have a mechanic retune the bike? Will I lose much power?
Thanks for your input!
 
....and wonder what, other than exchanging the two systems, I need to do. Should I change engine timing? Have a mechanic retune the bike? Will I lose much power?

To answer briefly and succinctly.....

- No
- No
- No

I would, however, reconnect the O2 sensor. The bike will likely run better than with Ztech exhaust.
 
I had a 96 RT and replaced the exhaust with a Super Trapp muffler. This was a disaster with zero improvement in performance, worse gas mileage and it was too loud. Guys behind me registered complaints...
I'm assuming you have a US model and not Canadian (Euro spec) for that year. They are different and actually have no O2 sensor and instead have an CO2 trimpot to adjust idle emissions. They also have a yellow Cat Code Plug in the fusebox.

When you put the stock muffler back on you will need to hook up the O2 sensor if it came with one. US models did in 97; I am pretty sure of that. Along with that you will need to install the yellow cat code plug in the fusebox or make one with spade connectors and some wire. This is the one from my 96RT which had no O2 sensor:
P1010976.jpg

Notice is has only one jumper; pin 30 to pin 87. If I recall correctly the US models had a three way jumper that connected pins 30, 87 and 87a. Someone with a US model RT can confirm this for you. I played around with various jumper settings and tested a bunch of them from a GS cat code plug map chart for various models and configurations in efforts to purge the surge. I ended up back at square one with the default plug which was golden yellow in these Euro spec models.

Where stuff goes...
Fusebox Map:
R1100FuseBox.JPG

Once done with this stuff you should tune the bike. This will involve setting the valves and synching the throttle bodies. Timing remains the same. I would confirm it is correct but if no one has messed with it, should be fine as is. Basic mechanical skills and a set of carb balance stix, tubes, Harmonizer, Twin Max... is needed to synch the throttle bodies. Adjusting the valves requires two sets of feeler guages like these to do a proper job. https://www.beemerboneyard.com/wurthoilhead.html
If you are not comfortable doing this stuff, find the local BMW club. Tons of members are out there willing to help. And you can ask questions here whenever you need to.

Hope this helps!
 
I blew out the OE exhaust on my R1100RT and went with an aftermarket.

Hated it.

From the advice I got here, I put a good/used OE from EBay on it.

Quiet again, cold engine stumble gone and my fuel economy came back. Best part, all in, $375.00 CDN.
 
I had a 96 RT and replaced the exhaust with a Super Trapp muffler. This was a disaster with zero improvement in performance, worse gas mileage and it was too loud. Guys behind me registered complaints...
I'm assuming you have a US model and not Canadian (Euro spec) for that year. They are different and actually have no O2 sensor and instead have an CO2 trimpot to adjust idle emissions. They also have a yellow Cat Code Plug in the fusebox.

When you put the stock muffler back on you will need to hook up the O2 sensor if it came with one. US models did in 97; I am pretty sure of that. Along with that you will need to install the yellow cat code plug in the fusebox or make one with spade connectors and some wire. This is the one from my 96RT which had no O2 sensor:
View attachment 67844

Notice is has only one jumper; pin 30 to pin 87. If I recall correctly the US models had a three way jumper that connected pins 30, 87 and 87a. Someone with a US model RT can confirm this for you. I played around with various jumper settings and tested a bunch of them from a GS cat code plug map chart for various models and configurations in efforts to purge the surge. I ended up back at square one with the default plug which was golden yellow in these Euro spec models.

Where stuff goes...
Fusebox Map:
View attachment 67845

Once done with this stuff you should tune the bike. This will involve setting the valves and synching the throttle bodies. Timing remains the same. I would confirm it is correct but if no one has messed with it, should be fine as is. Basic mechanical skills and a set of carb balance stix, tubes, Harmonizer, Twin Max... is needed to synch the throttle bodies. Adjusting the valves requires two sets of feeler guages like these to do a proper job. https://www.beemerboneyard.com/wurthoilhead.html
If you are not comfortable doing this stuff, find the local BMW club. Tons of members are out there willing to help. And you can ask questions here whenever you need to.

Hope this helps!

Amazing response!

I wish that everyone who wanted to toss the stock exhaust could read this post first.

E.
 
Learned all these things from the school of hard knocks and mistakes. Folks like Paul Glaves, Matt Parkhouse, Roger04RT, GSAddict are but a few of the many, many people on the MOA forums that have passed along knowledge and how to info for years and they continue to do so. It's a great community and a great place to read and learn. So giving some back when a topic comes up that you've been through and already made all the mistakes is a no brainer.

I should mention that fusebox map was posted here and elsewhere on the net however I do not know who made it. They should get credit for a great idea and layout!

First time I saw it I printed it out and got another surprise. It fits perfectly under the lid of your fusebox. So I covered a printout with clear tape on both sides to water proof it and then taped it under the lid so whenever I want to pull Fuse 5 to reset my Motronic or check a relay the position, value and function of each fuse and relay is right where I need and use it. So all you 1100RT riders go ahead and grab it. Just hover over the jpg image, right click and then select "Save image as" and then select where you want it on your device for printing. Or just keep it handy in your cell phone.
 
I wish that everyone who wanted to toss the stock exhaust could read this post first....

I've had Remus and Supertrapp systems on three boxers and have been very happy with the sound, the quality and the reduced weight. The Supertrapp is also adjustable for sound.

On my last two bikes, the systems went on before the bikes came home.
 
Thanks to All!

Wow. I'm continually reminded of what a great group of folks own BMW bikes, and belong to the MOA. Many thanks to all for your input on my "exhausting" muffler question. I rode 1050 miles with 3 friends last weekend from Cincinnati, OH to Haiwassee, GA for a rally. My ears are still ringing from the Ztechnic exhaust. LOL. I'll take the most common advise and go OE. Special thanks to Happy Wanderer for the comprehensive technical advise. Happy riding to all!
JWS
 
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