I read somewhere that themason put k1100 throttle bodies on a k100. I cannot find that particular article so my question is can it be done and if it can what do i need to change. I have seen the K1100 TBs and they have hoses on the rear of each TB + the pressure regulator is different.

What or who is 'themason'?

There are quite a few differences between the K100 and K1100 throttle body systems, the most obvious being that the injectors spray straight into the intake manifolds rather than the cylinder head, ala the 8V K100. The 'hoses' you mention is the fuel feed rail on the inside of the TBs instead of the outside as in the earlier system. Will the simple switch-type TPS attach correctly and work on the TBs of the K1100? Do the 'flexi' air intakes of the K1100 TBs attach properly to the airbox upper of the K100? There are an awful lot of 'I dunnos'.

I should think it would be a nightmare task unless you were able have all of the bits and to pick and choose what you need from each system and to know then which pieces will work together.

I've looked for an article such as this as well and have found precious little on the subject. One thing we know is that they are slightly larger in diametre to the K100 TBs, so this might give us a bit more go accompanied by a freer-flowing exhaust and some practical way to enrichen the fuel/air mixture at varying rpm.

Have any of you done this mod?

Now I know what or who 'themason' is. I'm still looking for that TB swap though.

http://f3.webmart.de/f.cfm?id=2385371&r=threadview&t=3603281&pg=2

It gets better...

"Next, learn the dark arts of L-Jetronic. Inside the air flow meter are
two adjustments. One changes the pre-load on the vane return spring and
the other changes potentiometer position. Google up some automotive
websites on L-Jet and read how to make these changes. The car guys only
figured this stuff out three decades ago. Basically what you are trying
to do is reduce the spring tension ( only one click on a stock K-bike )
on the vane so it opens more quickly, speeding up throttle response
greatly, and by changing potentiometer position you change pulse length
and hence mixture for every vane position. Be very careful which way
you move this little chingus, consider where the vane will be after you
lighten the spring, you don't want to have raw gas dripping out the
exhause pipe, it's excruciatingly sensitive. Expect to take a few
Mulligans on this adjustment ( geez, did I really just use an example
from golf to describe a K bike ??? ) Be patient, you can do it.
Stage two is to remove the stock 33mm throttle bodies and graft in 35mm
throttle bodies from a K-1100 throttle body rack. You loose the TPS in
the process but I guarantee you won't miss it once you feel the big hit
of midrange this set up gives you. Now you take another click of
tension off the vane return spring and spend endless more hours fooling
around with potentiometer positions. Have fun guys, I told you most of
my tuning secrets. Oh yeah, enjoy the intake honk above 5000rpm when
it's breathing through the bigger holes. Who cares what the exhaust
sounds like? It's your own little crotch symphony."

That's enough for the day.

The forces of darkness are gathering and with each daily pass of the Postie my pieces and parts are arriving. The K1100 TBs are now in hand. The job will be an interesting one. There's an obvious but not daunting height difference since the K100 TBs slip into a shortish rubber flange and the K1100 TBs slide into a longer, larger rubber flange with a hole for the injectors. I have most of the bits and pieces to do minor surgery with. I can see that of the two bikes the lower half of the airbox is the same part number, but I may have to use the K1100's upper air box half if the original K100 upper half doesn't 'reach' down enough to slip over the K1100 TB mouths. As is typical with similar BMW models, a lot of the pieces mate right up with no dramas. Too, there are stacks of airbox/fuel injection bits on eBay in the US, UK and Europe going for a song. As well, there are heaps of later TBs if anyone else thinks this is a really stooopid idea and wants to have a go at it themselves. Can't resist, can we! (Rhetorical question).

The seller included the fuel pressure regulator, which is a different part number from the original K100, and mounted such as to interfere with the back of the rail due to the TBs being mounted differently on the K100. I can fab a piece of bracketry to hold the FPR in an adequate position. The TPS came with them too, which will be redundant on my K100 with its simpler function, and the attachment point is different between the two of them, which we knew beforehand. Does anyone need a good, second-hand TPS for Motronic?

This should all be fun as my 20mm front brake master cylinder, reach-adjustable brake lever, hydraulic Venhill brake lines, later-style throttle tube and accelerator cable are all enroute to the land Down Under as well. I have already the four-pot Brembo callipers and modded 292mm Suzuki brake discs, plus aluminium spacers to centre the new discs in the middle of the callipers. Next stop, later style wheels and radial rubber. This bike is a keeper and having recently ridden and compared the new bikes I can say that the 'feel' of the old girl is such a good fit that I'm not letting her get away. She simply needs some subtle refits. And more to the point, so do I.

I foresee a grand weekend on the tools in my immediate future. Skinned knuckles, dirt under the fingernails, and pictures to follow.

What do I hope to accomplish by not leaving well enough alone? Change for change's sake.

sounds good twb .....ifn you need help i can be a good "gofa"......(goes for this and that) .

lets face it , operations like this always need more than 2 hands to hold that thingy whilst fitting it up .

I have actually finished changing over to the 1100 throttle bodies on a k100. It is not hard at all.The 1100 TBs are the same as the k100s except the inside has been machined for a bigger internal diameter. I have left the tps off for the moment , in the near future I will get a friend to mate up the 'old' tps to the 'new' throttle rack.
It is a worthwhile change. I find the bike has a lot more go in the midrange(suits my riding style).

That is good to know! I look forward to diving in and Charlie, you're welcome to lend a hand. I might have a squiz at the TPS mounting point first so I can use it straight away.

Midrange improvement is what I am seeking. Thanks.

this all sounds too easy .....rusty says the tbs are about the same external diameter.....wow ...way cool



question for rusty ....from what i can assume ....the mix/afm wouldnt need to be changed much for a good reading .....what was your experience rusty ? did you need to make alterations ?

My exhaust always has evidence of a rich mixture at the tip so I'll see how she goes at first. If need be I can whack it onto an exhaust analyser and fine tune it. The diametre difference is only 2mm per TB, x 4, of course and this will certainly have an effect. I would be curious about your experience with fuel/air mixture changes as well.

I put in bigger fuel injectors (bosch 0280150710 from memory). Fuel consumption is higher but I find the trade off worth it.I used the old type rubber 'manifolds' and changed the throttle cable plate (don't know its proper name) from the k100 tbs to the 1100s. I didn't change anything else (spark plugs are still a nice tan colour). The only thing I found a bit frustrating was the one use clamps. I ended up buying the tool to put the new ones on( couldn't find any adjustable clamps skinny enough to fit).

Charlie came over yesterday and we had a good comparo between the two TB arrangements. From what I can see now that I've found the time to clean up the dirt, carbon and oil residue from the K1100 TBs is that the TPS mounts are the only real difference. The later Motronic TPS just use a wider mounting point than the earlier TPS. Grinding off a small amount of non-critical aluminium from the number one K1100 TB with a Dremel, then removing and screwing the steel K100 TPS mount to the K1100 TB mounting rack should allow us to use the earlier TPS on the later TBs. The switch area of the two TPS appears to be the same. The K1100 TBs also have a 6mm port vacuum balancing tube across the back side and they could either be capped off individually or just continue to use the balance tube and cap only the end off, retaining that nice feature. The smaller vacuum ports on the front side are there for running balance once they're fitted.



Another thing under consideration is to simply unscrew one side of the TB mounting frame at a time and swap it to the K1100 TBs so as not to disturb the alignment or adjustment of the TB running balance screws. The job looks more of a cinch than imagined and that's confirmed by those who've been here before.


Here are the great big bloody vacuum ports across the back side of the K1100 TBs. I'll either cap them individually or connect them up with short lengths of vacuum hose and two tees for improved equalisation whilst running.


The protruding bits of aluminium on the right hand end hold the Motronic TPS. I'll grind this off so the steel TPS mount from the K100 can attach to the two screw holes in the frame on either side and the original TPS will then work with no dramas.


I whacked a micrometre into the bore of the K1100 TBs to confirm they are indeed 35mm inside diametre. We've confirmed that the throttle cable flange will have to be fiddled with or exchanged but fortunately the two aluminium sides of the mounting frame share the same drilled holes so swapping this and that should be easy between the TBs. I will be using a 20mm master cylinder and later type throttle tube, and therefore, later cable with this set up and can see that the cable won't easily point at the TBs due to the size and bulk of the original upper airbox, but we reckoned we could change that angle. All part of the fun and games of parts interchanging. Who was the mountain climber what said when asked why he would climb Everest, he responded "Because it's there". He died on that trip and they've only just found his body! I'm glad we're not charging into totally new territory guns blazing.

Just to let you know...I've moved this to the Engine and Transmission section as it may have got overlooked in Humor.

good work blakey .....i guess if any body goes looking for it .....they got a chance of finding it again huh ?

I'll go wherever it goes, Mr Red Bike. Nice havin' some power, eh? As long as it doesn't corrupt absolutely. :queen:

got some 1mm stainless for the tps adaptor plate mate ...its all good

Goodo. We might not need it since the steel plate from the K100 unscrews and aligns with the K1100 mount, but...

There's always a but.

The lesson's in the doing. Man did I get taught today! Firstly that my muscles and joints don't enjoy the up and down and reaching for the tool way over there as much as they used to. I'd better keep at these projects, though lately they're every coupla months instead of weekly. I need to do this sort of thing more often in order to build 'em up.

I spread out the tools and the K1100 TBs bits and went to work. Having replaced the intake rubbers and upper air box rubbers about nine months ago I thought I'd a good idea what I would need and what I was getting myself into. The old stuff came out easily.

The new TBs are 35mm, just like the originals, but as the man said their bores are 35mm all the way through, unlike the K100 bores which are stepped about 1mm or so less. So it's the throttle plates themselves which are bigger on a K1100. The K100 TPS ain't gunna no how no way work on the K1100 TBs. It is totally different. Its actuating area is a half moon. The K1100's actuating area is a flat bit. I have an idea of what to do about it but will leave that for later on, lest I make a fool of myself (that ain't hard to do!).


Note the 1mm machined step inside the K100 TBs (top). The K1100's TB (lower) will flow marginally more air in comparison. You can see in this picture how the throttle cable actuator cams are different too.

Since I was fitting the TBs and needed a new throttle cable I also decided to fit the 20mm master cylinder, braid brake lines, four piston Brembos, and 292mm Suzuki discs. That bit went easily. I have only to do a further bleed tomorrow when the sun comes up again to get some trapped air out and we're laughing. I'm sans garage these days so it's all done under feeble porch light or brilliant sunlight.

It's the later throttle cable attachment at the TB end which is giving me the shites. The upper airbox from a K100 doesn't have the same clearance as the K1100 upper airbox. The throttle cam on the K1100 TBs makes the cable come in at a different angle. Can't use the original cable due to a different attachment point at the throttle end. I'm might have to fab something tomorrow to make it work. The more I angle the original K1100 cable holder inward the more it makes the throttle bind. I reckon an easy way to go would be to obtain a K1100LT throttle cable for its extra length and just drop it over and down the upper airbox instead of under it and leave the stock K1100 approach the way it is supposed to be. Now where will I get one of those on a Monday morning? I don't have one in stock at work.


Note how the original throttle cable comes in under the airbox upper at an angle and is attached to the TB frame from the inside as opposed to the later bit which is attached from the outside. The K1100 throttle cable must come straight down. I tried bending inward to sneak under the airbox upper but she's a no go. A longer cable from an LT might work simply because the extra length might allow the cable to go straight over the airbox and down. If I trim the TB end's plastic base down by half that might give me sufficient clearance to stick with the original TB end throttle bracket. We'll see tomorrow after a good sleep and time to think about it.


The K1100 has a honking great big bloody 6mm vacuum connector on the back of each TB. They draw vacuum in one big swig from each TB instead of a little puny sip off the last TB like the K100 does. The fuel pressure regulator (a different design) is attached to them through a rubber hose with four inlets. I removed this rubber bit and capped the TBs all off, staying with the original fuel pressure regulator's design which draws vacuum off the last TB.

It lives! I had a dream about what to do last night and when I woke up everything fell into place. It's good to walk away when you've had enough, it gives a man time to think on it. Of course the bench grinder and vise had a fair bit to do with it.


The original flange that the cable end slips into was used, as Rusty said he did, but I had to modify it to clear this and that. I reduced the top end 5mm and took off 2 mm underneath, then a small clearance was ground away to clear the inside of one of the intake spigots on the upper airbox where the clamps sit. The centre tab or leg that stops the metal cable holder from dropping was relieved of 3mm of metal and the whole thing was bent forward in a vice about 4mm. The throttle spins freely from idle to full and nothing binds. Here's a short video clip of the bike running with zero adjustments done to the throttle bodies. I need to tweek it, for sure, but it idles fairly evenly at 950rpm and revs right up with no complaints. I know it's my imagination but it sounds meatier, more burbly already when I give it some cane. LOL



Here's a short clip of only the second firing up of the bike after the TBs were fitted and with all four of the airscrews set to the most basic 1-1/2 turns out as recommended. It idled fairly smoothly and settled into a 950RPM throb. The Twinmax is going on them next to syncronise them properly.

The TBs are syncronised. I used my faithful Twinmax and set them all off number one cylinder. The three other cylinders were all needing a slight tweak inwards on the airscrew a quarter to a third of a turn to match. The idle didn't change and she revs to the moon without much wavering of the needle. I reckon I won't have to delve into adjusting the individual TBs at higher revs.

Now I'm bleeding the new brake system I've fitted and going out for a ride round the backroads of my rural neighbourhood, see how she feels over the road.

Rusty is right. The bike now has more midrange power, but he was understating it, I reckon. It feels like you're in fourth gear when you grab a handful and accelerate at 100 kph but instead you're in fifth gear and it builds quicker. There's more up top too. A lot. My old TBs always synced up all right, but these TBs are smoother. That long-time irritating vibe at 3300 and again at 4400 RPM isn't there any more.

Any drawbacks? I sense it has slightly less urge under 3000 RPM. I don't cruise round at that RPM much anyway, and if I need to go right now I downshift. It'll be interesting to see how and if my mileage changes much. She was always a petrol sipper. This weekend I'll take her out on an all day, full tank ride, see how she goes.

The brakes? I'm going to have stiffen the front end. They bite so much better and have a more progressive and aggressive 'feel' and the front end dives more quickly under hard braking. I'll try 10W fork oil first as I'm currently using 5W. I suspect it'll all fall together when the radials and wider rear wheel are fitted.

Woo bloody hoo! I like a definitive fix.

Grrrrrrrrate Mate good to hear and what do you reckon about lunch at Greenmount or elsewhere

nice one twb .....great news .....woha the brakes as well ....smooth



how did the tps work out ?

I work Saturdays (the motorcycle biz!) but Sunday I'll be up for a ride and lunch in Greenmount. I'll see if I can drag Charlie and maybe even Blakey along with me? Who else is up for it? Two red bikes, a silver one and something else too. Are you riding now with those wrists still in healing mode, KF?

The old TPS is attached to the back of the current TBs doing nada, nichts, nothing. The little widget that turns could easily have a thin aluminium disc adapted with the appropriate cut out on either side. I'm gunna give it a think over, make some sketches, see if I can hammer one out with my stone chisel and mallet. I liked the way it felt without it though, the revs drop quickly and it's not as 'jerky' at low rpm.

Brakes! It's good to have some. That span-adjustable 20mm master sends the signal right quick to those four piston Brembos clamping the old Suzuki discs. I'm stoked. Actually looking forward to the commute to work tomorrow morning.

Life feels sweet tonight. the old crow is cawing up on the fence, a gaggle of kookaburras are laughing insanely away in the tall trees, as they do, the sun's setting and this glass of single malt is warming me as the temp drops for the night. My bones and muscles ache satisfyingly too. Getting older's all right when you get some things done along the way.

Great work on the TB;s and the brakes!
Unfortunately I'm of to Adelaide in the cage for two weeks starting Sunday, taking the cheese and kisses and one of the billy lids.
I know where I'd rather be...

If Blakey can come how about Merringandan. That would be a bit easier for him and they have a really good spread there.

Wrist is comming along well and I need to get some riding in before Araluen. I will be trying to modify the bars to fit me a bit better too.

You'll be missed, old sod. Have a great road trip down through our big and beautiful country. We can all use a bit more of that.

This very nice extra oomph from the Mighty K has my imagination running...there's a coupla sets of 38mm K1200RS/GT throttle bodies on eBay at the mo'...as a project in my spare time...grab a clean second hand cylinder head, go over the valves, seats and guides...give it a thorough port and polish...slip in some 'bigger' injectors...open up the exhaust just that tiny little bit...the need for speed is a powerful intoxicant...
:bom:

lols ....this sounds like 20 year old behaviour ...or is it just the inner self of the typical "rev head" ?...dont matter to me ....i have had the same thoughts as well ...



id be thinking that twb is a happy chappy no ?



a great success ....good work mate !

I have no lame excuse, Charlie. I like power. It's intoxicating like a good drink or a strong drug. The trick is to not give the 'bike too much stick at inopportune times and cop a ticket or worse, a nasty prang. I don't always use the power I've helped to create under me, I just like the fact that it's there to tap when I want it. Ever since I can remember I've had a bit of grease under my fingernails from some project or other. I'm happy with tools scattered about me and inspiring ideas brewing in my head about how to change something that works perfectly well as it is. Yeah, happy chappy indeed, even the daily commute was fun today. Cheers.

After several days of riding the bike to and from work (and taking the long way on winding country roads when I can) I've got to say that it is a really worthwhile mod to do and relatively easy too. The power always seems to be right there when you need it, more lively, revvier, and with a satisfying throb due to the bigger volume of air passing through the TB's larger openings. My petrol gauge hasn't moved much more than before the swappo but this is not yet a scientific measurement on fuel usage - my right hand is in it more too! I'm gunna take an honest crack at determining mileage this weekend when Charlie and I ride out through the hinterlands to meet for a pub lunch with our recuperating mate, K Freak.

I found my K1100 TBs in the US on eBay and asked the seller if he'd discount the 'Buy It Now' price if I didn't get the TPS which was included. He agreed, dropped the price fifty bucks, then sent it to me anyway, which I've now re-sold on eBay myself. All up with new one-time use clamps and a spray can of carbie cleaner I might have $170 into the TB upgrade project. I don't factor in my elbow grease cleaning things up, or my time fitting and fettling them. Oh, and I whizzed out a couple of the sparkies last night and they're a nice, very light brown colour as usual, and no pinging whatsoever occurs, so she's not too lean. Although I have not stuffed a sniffer hose up her bum to check the exhaust mix I reckon no fuel adjustments to the AFM are needed at this stage either.

For the C and RS models at least, which when compared with the typically more touring oriented, bigger load carrying, passenger toting RT/LT, which needs the low end grunt, I feel that this is the way they should have come.

But in my quest for something different, I've still got me eye on those loverly looking 38mm TBs from the early K1200...

My used 3 spoke front wheel rocked up with the postman today from Arizona. I excitedly unpacked the well-packed box only to discover a brand new wheel inside! I was gobsmacked. No wonder he didn't want to come down on the price!

Now to match the paint front & back and swap the new brakes and spoon the new radial tyres on...Gunna be an exciting next coupla days.

wow what a win by chance twb ....im happy for ya.....cheers mate !!!

Yeah, pretty bloody surprising to me too. The bloke named JD (from Iron Horse BMW in Tucson) was wary of posting out of the country and to persuade him I emailed him the link to the US Customs site where the proper form is available. He reluctantly gave it a go and in about ten days time I had my wheel, insured, well-packed, and to my door. I recommend the man for any odd bits and pieces you might need. Here's a link:

www.beemerbits.com

7AM Sunday morning, got about three hours 'til the MotoGP madness from The Island starts on the tele. Cuppa tea in hand, sunny and warm, t-shirt weather. What better time to whiz out the old, crusty (but functioning perfectly) 133cc per minute fuel injectors and replace them with a set from a low-mileage 2002 K1200RS!? While I'm there I'll re-check the TB sync with the Twinmax. Spot on.

What ya do that for? The sparkies have been looking a tad white round the ceramic. Though the bike runs well and returns good mileage I reckon she's needing a bit of extra juice to chew. Working in a high tech motor shop there's no tail pipe sniffer since new cars are so computer integrated so mucking with the MAF seemed a fair stretch of hard yakka. I got these FleaBay 150cc p/m injectors (same part number as a K1100) for cheap dosh from the Land of the Free. They're in, new O-rings and all. The bike idles well and revs up with zero lag. I can imagine a meatier idle as she sat there idling up to verifying the fan definitely will come on, twice, whilst I screw the panels back on, but there's a tendency to wishful thinking from my small kingdom. A ride to prove them is coming up in a short while. All up it's taken me an hour and a half, and what a load of sand and debris round the injector ports. That was a careful clean up. Cheers.

Nice; a bit smoother, definitely revvier, happier at part throttle and that mildy buzzy 3500 rpm bridge has diminished. A full tank of petrol, the daily commute for the week and we'll see how much she sips now, though my right hand is in it harder 'cause it's more fun with more power.

Now for a nice grind on the cams and and and and................ it never stops.

It's exhausting....Hmmmm....that's next.

Two Wheels Better wrote:Nice; a bit smoother, definitely revvier, happier at part throttle and that mildy buzzy 3500 rpm bridge has diminished. A full tank of petrol, the daily commute for the week and we'll see how much she sips now, though my right hand is in it harder 'cause it's more fun with more power.

lol ...you old revhead ....giggle .....nice work !!!

How 'bout that racing at The Island!? Honda, one, two, three. Advance Australia Fair resonated.

Yep a top result Kid Casey does it again.

aye !! ,,,great result

They must have found that missing bit of Jorge's ring finger since the medical report from Melbourne suggests he'll regain all feeling in the finger.....or were the crew and corner workers simply looking for an expensive or cherished ring in the trackside gravel trap?

Nice work with this mate and I luv the clip! Oh, and great result on the Island as the Kid does it again!!

OG

Couple of questions. Too bad TWB isn't active on this forum any longer; I'd really look forward to his advice.

I'm seriously contemplating changing out my K100 TBs for K1100's. So, that means I'm in the market for a K1100 throttle body assembly. About what aspects of a throttle body's condition should I be alert when getting ready to buy? Generally what's available in my budget is in used condition and possibly already long separated from the original engine, so parts may have gone missing or the assembly could be incomplete for the conversion. I am guessing all I need are the TBs themselves, rubber bushings, the support rail with bell crank. Anything else is superfluous. I'm also guessing that the butterfly valves should not have been altered from factory settings.

TWB was not specific about how he solutioned the throttle cable support. I think he fashioned a K100 support to fit on the K1100 assemble in place of the original support. But where and how he fastened the thing or routed the bowden cable is unclear. Does anyone have that knowledge that they can pass on and advise me? The advantage I currently have is that I'm using a K1100 front master cylinder and throttle, meaning I'm also presently using a K1100 bowden cable. This might make my conversion easier, I'm hoping.

TIA.

as you say rob the cable entry to the throttle bodies is set more vertically than the k100 ....the rail support at the back of the tbs is verry similar to the k100... i have the feeling that he modded the k100 bracket socket part ..by drilling it so it sat slightly deeper fit

i think he took some pics of the mod he did and ill ask about them


i believe all the rubbers are standard k100 as the k1100 has a different injector setup


the one thing he hasnt resolved so far is the tps ....the one on the k100 is half moon the one on the 1100 is a slot we had thought to fashion an adaptor but no work has progressed yet

in addition he went for the bigger injectors ....but his bike always ran a little leaner than all the rest round here ...he reports that it is a well suited suggestion for his situation

if there arent any pics available ill run over and get some when i can

i believe he did something about the cable lengths as well ..vaguely i think he routed the cable differently to acheive the fit instead of through the head part of the frame ...a more direct route straight under the tank was used (this may indicate that the 1100 cable was used )

i would be carefull to try and get a tb setup that didnt show any signs linkage pivot shaft movment through the actuall bodies

i also believe he blocked all the extra vacume outlets on the throttle bodies that the k1100 has (they run a different vacume to regulator setup with all 4 tbs connected )

i hope that helps some ... know its not real specific ...but i didnt actually see the mod performed.... but have it on my list of things to do

This is a teriffic read and the results appear to really please. Really glad it was moved to where we were lookingPlus I was wondering if a port job would be nessassary to match the TB's Keith

Psst.. themason is on


Thank christ....what a pain he is.... Ajays

charlie99 wrote:i also believe he blocked all the extra vacume outlets on the throttle bodies that the k1100 has (they run a different vacume to regulator setup with all 4 tbs connected)

It isn`t that important at all, but these vacum connections is a part of the crankcase ventilation system.
It`s a separator in the top of the airfilter housing, these connections is the gas return line.
The oil is feed back to the engine through another hose.



And since Ajays mentions Flying Brick, it`s a thread there about mounting K1200 TB`s on a K1100, which could be interesting reading to some.

Inge K.

good information inge ....thanks

learning all the time

rob try pm to "guest in the house" (aka twb )

Two things I did were to grind the 'brace' under the original cable bracket so that the bracket leans in more, providing the necessary angle, and ground away the tip so it fits between the plastic intakes. I also modded the TB end of the cable by carefully cutting away enough of the two layers of nylon so there is sufficient freeplay. The pics I posted in previous posts clearly show what I've done and my previous description is detailed enough to work out how to do it for yourveryownbadself. When you have all the bits to hand it'll become clear. I too am using the 20mm K1100 master cylinder and throttle cable.

As for fitting K1200 TBs to a K100, holes would have to be delicately drilled and tapped for air screws since nought but the castings exist there now. Be sure to source the 38mm variety (which came with cruise control models) and not the minimally increased 34mm versions.

35mm diametre K1100 TBs are the best overall ride-ability performance mod I have done to my K100. Eventually I will sort out an adaptor for the TPS, but for now it's not missed.