Hello,

Either my google-fu is lacking, or there simply doesn't seem be much information regarding K100 exhasut interchangibilty. Perhaps it's because it's a simple question; but I am new to BMW bikes.



Is there any difference over the years/packages regarding exhasut fitment? For example, would a 1991 K100 RS (16v) system fit a 1985 K100 (8v)?



Any insight greatly appreciated! Thank you.

Yes but the rear mounting is different. Not an insurmountable thing but different

So it's just an issue of fabricating a rear mounting bracket? The headers would bolt correctly up at the engine?

You may have some issues with the K100 centre and side stans so use a K1100 one

Rick is right, and the 'stop tabs' for the stands will be in slightly different places. The headers (spacing, etc) will slot right in, though. That ungainly bulge in an OEM K1100's middle section will occupy the space intended for the older stand, and the rear mount will need fettling, for sure. But nothing about it can't be overcome.

A if you intend to get one, the support on the bulge in the middle section is quite important....be shure you get it with.

[quote="Inge K."]A if you intend to get one, the support on the bulge in the middle section is quite important....be shure you get it with.[/quote]

The center stand mount on 16V bikes has a threaded hole into which the rubber isolated rear support screws in. DO NOT omit that mount or the exhaust will very quickly develop cracks where the header pipes are welded to the collector. Once they crack you cannot repair them. I have seen a few older Ks with later 16 valve exhausts and round mufflers. The rear mount can be made to work with minor fabrication.

Consider having a competent welder run a small bead of material, like a little metal thread, between each header pipe 25-50 mm up from the collector. This seems to dampen the buzz that cracks the welds at the collector.

Themason wrote:The center stand mount on 16V bikes has a threaded hole into which the rubber isolated rear support screws in.

It is a L shaped bracket mounted on the rear right bolt to the center stand bridge which is used for this support. (both bracket and rubber support shown at the drawing).

Bracket, part #18 21 1 464 152.

Been thinking about fitting the K1100 exhaust too. for no other reason then that it looks better. I already have the 1100 stands on.
So if I get the bracket for the stand exhaust mount, what will I need to do to get it to fit up to the Footpeg mount??
anyone done it? pics?

cheers

Forget it andy you will be fixing cracks for ever till you have a solid 40kg lump of weld with 4 holes in it. I have had to weld mine 4 times in 13000km and it was falling to bits when I got it

oh.........................damn. Maybe just a motard muffler, or one of those magaphone units off ebay.
dont see many of the motard mufflers second hand come up.
we can discuss it over a drink Saturday!

drive carefully!

I made a collector for the K100 and used a laser can from a kawasaki system and that is what is going back on the K1100 because I found another crack when I removed it yesterday to take the head off.
And it sounds just magic and with the baffle taken out it is just like an R1 in full cry.

Hmmmmmmm, if I go ahead and do it though, what will I need to do to get it to fit the footpeg, anything??
I'll still have the old exhaust system to replace it with if it cracks up.

I reckon you would have to fabricate your own mounting. The K1100 has a triangular plate that bolts onto the gearbox where the 2 rear bolts for the footpeg plate bolts on a K100.
The Mufler on the K1100 has 2 6mm bolts holding the bracket to the muffler, you could make a plate to fit there that picks up the bolt on the bottom of the OEM K100 rubber mount.

Bugger! you were 'sposed to write "nah it just bolts right on up" !!
Ok, will have to look at this a little closer another week. cheers mate.