K11 Owners Group

goldust · Posted: Wed Apr 01, 2009 8:26 am Post subject: butterfly sync

i am looking for the butterfly sync directions.
i have heard they were on the bmw tech site some time ago, but were taken off. i have done the carb sync, but that has not helped that much.

tmoons · Flying Brick Rider Joined: 09 Oct 2008 Posts: 161

they where (as i believe the story goes) taken of because people did it wrong and blamed the writer (or asked him endlessly how to correct)....

I've not seem "those" instruction myself, i've just "stolen" bit and pieces from other sides and posts..

but i would be very interested to see how the original instructions hold up against the bits i found.

Furthermore, always be sure you do NOT have ANY vacuum leaks in the system!

RAL88 · Posted: Wed Apr 01, 2009 7:07 pm Post subject:

I have the original post. PM me your e-mail address and I will send you a copy.

Of course the disclaimer goes "I don't know what your abilities or experience is so I take no responsibility if you screw up your throttle bodies"

With that being said and out of the way I can say first hand that it is pretty easy to do. It improved my vibration and overall perfomance better than just synching the brass screws.

The $400 K100 that I picked up was most likely being sold because it wasn't running. He completely screwed up the throttle bodies and butterflies so it would not even start. That is probably why the bike came with another unmolested throttle body assembly as a replacement. Considering I had nothing to lose I figured that I would try and get the throttle bodies working again. It actually took me all of 15 minutes to put them right. What I did was close all the brass vacuum bypass screws. I then loosened all the "screws that shall not be touched" so that I could close all the butterflies until they bottomed out in the throttle body and used that as my starting point. Once that was done I followed the directions in the post and used the aft throttle body as my reference since this is the one that syncs with the TPS. Once I got them synced this way I tightened the screws and opened the brass screws 1.5 turns and then resynched with the brass screws. The engine is running like a champ and sounds good and strong.

Does anyone need a throttle body assembly since I will not need the spare.
_________________
Rich

"If it ain't broke, take it apart and make it work better"
*************
'96' K1100LT-SE
'97' R850GS-R

Stoked Steve · Posted: Wed Apr 01, 2009 7:36 pm Post subject:

I'm glad to hear the salvage K is being brought back to life, always great to rescue a "lost cause"! It's amazing what a little knowledge and some blind hope can overcome.

Post some pics of her if you get a chance.
_________________
Steve
Virginia Beach, VA
93 K1100RS Mystic Red SOLD
12 Suzuki DL650A VStrom

Flying Duck · Posted: Wed Apr 01, 2009 7:54 pm Post subject:

I found this on the MOA for a guy with a screwed up K100:

- First - do you have a manual, if so which one? If not BUY one right now. Clymer or Haynes.

- The bike needs to be checked for intake leaks. At 23 years old - you more than likely have some. Move the bike outside your garage. Have a fire extinguisher handy. Start the bike, let it idle. Take some FLAMMABLE carb cleaner spray and spray very small spritz's around the injectors and the throttle bodies. ANY CHANGE in idle indicates a leak. FIX THE LEAKS before going any further. Try not to start a fire - there is hot exhaust right on the bottom of the head. If you don't know if your skill level is good enough for doing this STOP and find someone who has the necessary skill level. I don't want you burning your house down.

- The bike has to have the valves precisely adjusted. You're going to be using the engine as an air-pump for a flow bench. Without the valve adjustment it just isn't gonna work. They have to be adjusted right, and the closer you can get them to each other the better this is going to work.

- OK - once the above is done - remove all the brass screws. Clean them and use a Q-tip in carb cleaner to clean the bores they go into. Replace the O rings on them. Screw them in until they *gently* bottom out - then open each of them exactly one turn. IF there are any steps on them from overtightening them - replace them. You can't adjust damaged ones.

- Remove the throttle-position-switch from the rearmost TB. We'll get to replacing and adjusting it when we're all done here.

- Connect the 4-channel vacuum gauges. Start the bike. See how it looks at idle. Since you've already misadjusted the inter-TB screws, we'll start there. Adjust these screws until all channels read the same. We're not worrying a lot about idle speed, but don't turn them all in the same direction. Balance the vacuum on them.

- Open throttle to 2,000 RPM. Do all of the channels change at the same rate? If not - you're going to have to adjust the inter-TB screws at 2,000 RPM until they do. Once you get that right, we're going back to an idle balance adjustment

- Once all channels look the same at 2,000 RPM, drop back to idle (~1,000 RPM). If the channels aren't balanced - use the brass screws to balance them out. You should not have any brass screw more than 1/2 turn different from the rest. If you do - then the inter-TB screws still aren't correct, and you have to repeat the steps above. (ALL brass screws should be between 1/2 turn and 1.5 turns out. None should be out more than 1.5 turns, and none in more than 1/2 turn.
_________________
93 LT (x2)
94 RS
86-97 K75F(K75/100/1100 Frankenbrick)
86 K75C w/paralever, hi perf cams,TURBO!
91 & 92 K75Ss
91 K1
86 custom K100
14 WR250R
IBA #17739 (SS1K, BBG, 50CC)
Buy parts HERE

RAL88 · Posted: Wed Apr 01, 2009 8:44 pm Post subject:

Here is a pic of the bike. I am in the process of tearing it down to the frame so I can paint the frame and then clean everything up as I put it back together. This bike looks like it was a daily rider and it seems the engine and drive train was taken care of but not the cosmetics.

_________________
Rich

"If it ain't broke, take it apart and make it work better"
*************
'96' K1100LT-SE
'97' R850GS-R

tmoons · Flying Brick Rider Joined: 09 Oct 2008 Posts: 161

WidgetMan · Joined: 23 Oct 2008 Posts: 11 Location: Derby, UK

Hi Folks,

As a newbie to all this I've a couple of questions that follow on from Duck's generous posting.

1) Where is the inter-TB adjusting screw for cylinder 4? Found bypass screw and bypass blead but no inter-TB screw. Is it under the TBS?

2) Am looking for the hints for adjusting the TBS referred to by Duck but can't find it. Any clues?

I've followed the instructions detailed above and seen significant improvement in noise and rock knocking using a single home-made manometer and alot of patience.I just need to work out how to reset cylinder 4 for a full house.

Thanks in anticipation.
_________________
'93 K1100LT (tatty and ex-police - the bike, not me!!.)
K - 75,000 miles, me - 4000 miles.

RAL88 · Posted: Sun Apr 26, 2009 5:11 pm Post subject:

I don't do anything with cylinder 4 and use this as my base to set the others by. I have found when setting the TBs that when you adjust one it changes the others. That is why I feel it is important to have a 4 gauge meter so you can see how the adjustments change the other TBs. I use a Carbtune and it works great with no nasty mercury.
_________________
Rich

"If it ain't broke, take it apart and make it work better"
*************
'96' K1100LT-SE
'97' R850GS-R

tmoons · Flying Brick Rider Joined: 09 Oct 2008 Posts: 161

There are 3 inter TB adjusters only!
1 between cyls 1 and 2
1 between cyls 2 and 3
1 between cyls 3 and 4.

start with 1and2,
than do 3and4
than do 2and3

indeed use a 4 column one, it helps!

WidgetMan · Joined: 23 Oct 2008 Posts: 11 Location: Derby, UK

Folks,

Thanks for your help with this - very useful, especially until 'Flying Duck' or someone can repost the definitive instructions. As an oh so poor student teacher I'll have a go at making a 4 pot manometer sometime over the next week or so. Using a single channel manometer is instructive in the art of patience and reveals a slightly disturbing masocistic tendancy......

I feel a previous owner has been messing in this area and the whole thing needs starting again.

I've got pots 1-3 in sync by using the inter-TB screws as gross adjusters and the bypass bleed screws for the fine. Pot 4 seems to be alot lower in pressure than the other 3.

My dread is that pot 4 is showing some leakage somewhere. I've sprayed around with engine starter fluid but cannot get a change in revs that would indicate an air leak into the cylinder. I'll try again next weekend. Any further hints or advice welcome.
_________________
'93 K1100LT (tatty and ex-police - the bike, not me!!.)
K - 75,000 miles, me - 4000 miles.