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TECHNICAL MOTOBRICK WRENCHING In Remembrance of Inge K. => Project Custom Motobricks => Topic started by: Borneoben on August 14, 2019, 03:15:30 PM

Title: K1100RS Exhaust fitment Questions
Post by: Borneoben on August 14, 2019, 03:15:30 PM
Hi Guys

I recently picked up a 1993 K1100RS that needs a bit of TLC.
The exhaust headers are cracked badly right at he point where they join the muffler section.
I know this is a common problem especially if the right side support bracket is damaged or missing. Mine was missing...

The plan for this bike was to turn it in to a Cafe Racer and as such the exhaust will be replaced.
However. My plan was to get the bike fixed up fully serviced and running in stock configuration before i start any modifications.
I want to make sure its mechanically sound before i spend a bunch of time and effort into the custom build. I would like to commute on it for a little while to sharpen my rusty riding skills and make sure the bike is not a lemon.

So. My questions are as follows.
I have found a replacement K1100RS exhaust system for a reasonable price that is a bolt on replacement.
The RS exhaust headers are permanently welded to the muffler.
The K100 exhaust headers are not welded to the muffler and are removable and so it seems forms the basis for the majority of modified exhaust systems.
Considering i will be installing a different muffler in the future sometime, should i just buy a K100 System now and install it ready for when i need to install a 4-1 collector and different muffler?
Can a stock K100 Muffler be fitted to the K1100RS?

Any constructive feedback you can offer would be most welcome

Cheers

Ben
Title: Re: K1100RS Exhaust fitment Questions
Post by: volador on August 15, 2019, 02:59:21 AM
You got a K100 2V or 4V exhaust system?

When you get the mirrors and centerstand off send PM I'm interested.
Title: Re: K1100RS Exhaust fitment Questions
Post by: The Mighty Gryphon on August 15, 2019, 07:19:29 AM
You can put a K100 exhaust on a 16V engine.  I installed a K100 exhaust on a 16V k100RS with no major problems and rode it for over 5,000 miles.  It takes a bit of fiddling at the rear mount, but the size and spacing of the exhaust ports on the 1100 engine are the same as on the 100 engine.

The problem with the retrofit is that footpeg plate is a little further from the centerline of the bike on the 1100 vs. the 100.  This causes the exhaust to angle out a little and reduces ground clearance when dragging the pegs by being the first thing to drag.  I solved the problem by spacing the mount about 1/2" from the back of the footpeg plate.  Put everything together on the bike before tightening anything starting from the exhaust ports on the head and working back.
Title: Re: K1100RS Exhaust fitment Questions
Post by: Borneoben on August 15, 2019, 11:16:17 AM
Hi guys

Thanks for the feedback. Its most appreciated.

The Bike is a 1993 K1100RS and the exhaust is cracked right where the individual manifold pipes join the muffler.
It seems this is a common problem if the center exhaust mount is missing or breaks.

I would eventually like to install a much shorter raised exhaust as shown in the attached pictures but i need to get the bike back on the road first before i strip it down.


So it sounds like the best option would be to go for the K100 exhaust system and figure out a rear mount for it plus weld in a threaded bung for the oxygen sensor.
That way i will already have the separate manifold i need for my intended exhaust system.
Title: Re: K1100RS Exhaust fitment Questions
Post by: Filmcamera on August 16, 2019, 09:35:27 AM
The exhaust on my K100 RS 16 v has cracked in the same place on two or maybe even three of the pipes.  It was a quick and easy fix for the local welding shop. I think it cost me $10
Title: Re: K1100RS Exhaust fitment Questions
Post by: Laitch on August 16, 2019, 09:45:58 AM
The exhaust on my K100 RS 16 v has cracked in the same place on two or maybe even three of the pipes.  It was a quick and easy fix for the local welding shop. I think it cost me $10
Were you using the hose clamp modification to prevent cracking; are you using it now?
Title: Re: K1100RS Exhaust fitment Questions
Post by: Frederick on August 16, 2019, 03:03:29 PM
Tell us more about the hose clamp process please?
Title: Re: K1100RS Exhaust fitment Questions
Post by: Laitch on August 16, 2019, 06:32:53 PM
Tell us more about the hose clamp process please?
Read all about it here (http://www.k100-forum.com/t10630-k-series-exhaust-headers-cracking-a-possible-prevention#125768), Frederick.
Title: Re: K1100RS Exhaust fitment Questions
Post by: Borneoben on August 17, 2019, 01:04:24 PM
Thanks for the replies guys.

I got good news today.

My buddy stopped by just to visit and we got to looking at the bike. He said he could weld it up for me no problems.
I didnt even know he could weld! Let alone have all the EQ on hand.

So problem solved for now.

Will also include a jubilee clamp around the headers to help it last a bit longer.

Cheers