K11 Owners Group

RAL88

I was able to get my pdf into a word document so here is the article on syncing the throttle butterflies or as he calls them the throttle plates. I can tell you first hand that this is really easy to do and makes a big difference on the smoothness of acceleration and really cuts down on the vibration even more than just adjusting the brass vacuum screws. What you want to do before you do this is put in a new air filter or at least have a fairly new one in, change your oil, fuel filter and spark plugs. Once you adjust the throttle plates you will never have to do it again. I use the TB closest to the TPS as my standard and adjust the other TB plates to this one.

The K100 that I got was not running at all because the PO screwed the plates up. What I did was loosen all the plate adjustment screws and let the plates naturally bottom out. Once I did this I opened the throttle a little, started the bike and it started right up. I then did this adjustment and the bike runs great. He gave me a spard TB assembly which I ended up not needing.

So this is really easy to do and the bike will run smoother than just adjusting the brass vacuum screws.

Moderators may want to put this in the tech stickies

K throttle Body Synching

By: Rob Lentini
June 1995
Here's a real simple way to ascertain whether your K's throttle plates are in synch--the adjustment we are admonished to never touch!
Attach a carb stix, other mercury synchronizer, or very accurate bourdon tube vacuum gages to each vacuum access port(covered by rubber caps and the fuel pressure regulator line). Connect the loose fuel pressure regulator vacuum line to the corresponding carb stix column (or gage) using a "T" fitting.
Warm the engine. Screw in and lightly seat all three (or four) idle bypass synch adjustment screws (count the turns in for each, and record). Doing this will slow or stall the engine, so actuate the starting lever (choke) to maintain normal idle speed**[see amended procedure below-wd]**.
When the screws are fully seated, any measured vacuum imbalance is then a function of variance in throttle plate opening ONL Y, and is adjustable from between the throttle bodies. If out of synch, carefully adjust to equalize all readings. At this point, increase RPM slowly and smoothly, checking for different readings at various engine speeds.
You should see little or no change, since adjustment at the smallest throttle opening is most critical. Once throttle plate synch is set, reopen the idle bypass synch adjustment screws (per your notes), and fine-adjust them to reestablish correct idle speed and synchronization with the "choke" lever off.
Following this procedure should not affect the adjustment of the throttle switch/position transmitter. Check if in doubt. On older Ks you're listening for an audible "click" just as the throttle returns to the closed position. Follow this procedure and your perfect throttle body synchronization will eliminate much vibration.

*AMENDED PROCEDURE*
I stand corrected! A few days ago I shared with all a procedure to synch the throttle bodies of K motors. In it, I suggested using the choke lever to maintain idle speed while the bypass screws were closed and the butterflies checked for equal vacuum (and adjusted if required).
Joe Senner and Tom Coradeschi pointed out a problem, one I hadn't thought about. Their contention was that the choke opens the butterflies from the aft end, while the throttle cable itself actuates from the center. Both guys said vacuum differences would be measured between these two methods, and opening the throttle through the twist grip was the correct way.
Anal as I am, I assured Tom I would verify his empirical data right away, so I jumped on the K last night to vindicate myself (everybody has an ego!).
Using my Carb Stix, I measured a 2-3 cm delta in the mercury column between injector body number 3 (the aft one) and the other two when switching from throttle to choke actuation. Whether this is enough to cause vibration or rough running is debatable. Yet, the whole point of doing the synch procedure is to "knats ass" the adjustment.

So, bottom line: Amend my procedure to use the throttle to keep the engine running with the bypass screws closed.
http://www.ibmwr. orglktech/throttle-sync. shtmI 11110/02
_________________
Rich

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

SugarHillCTD · Posted: Wed Apr 14, 2010 9:24 am Post subject:

Rich,

GREAT info. There are a few posters on the MOA website that would disagree with doing this, but it makes sense.

John
_________________
John & Cathy

'92 K100RS4V Pearl White SOLD
'04 K1200GT
IBA Several-SS1k, BBG, 50CC NYC to S.F.

Flying Duck · Posted: Wed Apr 14, 2010 1:00 pm Post subject:

Don Eilenberger post from the MOA:

miKeinWIs · Posted: Thu Apr 15, 2010 6:49 am Post subject:

Thanks Rich, I was about to contact you about the elusive article--not that I'd have the nerve to try it right now. But may do it soon. My home made two line synch tool should be upgraded to a real 4 line unit for peace of mind.

And to Drake for the extra details. That's what I've been looking for.

All a day too late. Will have to go back in to try again as I thought I'd read the brass screws should 1 1/2 turns out to start. Idle did come down some. The brass screws were more than spec out.

Getting good at taking the left fairing off!!

Thanks again
Mike
_________________
'97 K1100LT
Bought 6/30/09 w/26,750 miles

Ernie-NH · Posted: Thu Apr 15, 2010 5:22 pm Post subject:

I got mine via regular e-mail and it looks great. Like all such articles, I've archived it in a special "K Biker" shop folder !

Thanks again Rich....

Best regards........// Ernie-NH
_________________
AMA,, American Deaf Bikers
Airhead Beemers Club
'11 G650gs
'95 K1100LT
'76 R100/7

Ted · Posted: Thu Apr 15, 2010 7:02 pm Post subject:

Is that the PDF the IBMWR K-Bike tech pages someone copied and then started selling on eBay?
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Ted

KOG#1

RAL88 · Posted: Thu Apr 15, 2010 8:25 pm Post subject:

Hi Ted,

If you mean the one that I posted not that I know of. I copied it off of IBMWR about 9 years ago. When I looked for it two years ago it had been taken off of IBMWR.
_________________
Rich

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

Ted · Posted: Thu Apr 15, 2010 8:45 pm Post subject:

Sorry Rich - I am a bit sensitive to it as some of my contributions are part of that. I am pretty certain the PDF compilation was never available on the IBMWR site as a PDF (and I have been an IBMWR Admin since 1993.)

It started as someone compiling and selling the PDF as a DVD (incorrectly called a Maintenance Manual) on eBay, and then people started hosting the PDF on websites. We got most of the auctions cancelled and I had the PDF pulled from as many websites as I could. There is one club in New Jersey I have repeatedly requested they remove it, they have ignored my requests and a few weeks ago I contacted the ISP and filed a DMCA copyright complaint requesting the account be terminated.

I and many others put a great deal of time into creating those docs, and we did it for the IBMWR. Not for someone to make money on eBay and not to be hosted without attribution other sites. Also, I know of several articles that have been tweaked and changed, the PDF doesn't reflect those.

Anyway, it is a sore point Smile

_________________

Ted

KOG#1

RAL88 · Posted: Thu Apr 15, 2010 9:51 pm Post subject:

Sorry I did not know. Originally I printed a hard copy and have it in my K1100 ring binder. I never had an electronic copy until last year when I had my son scan it into his computer and save it as PDF. I just got done using an OCR program to save it as text so I could cut and paste it. I will no longer distribute it but I must say it has made my K run a lot better.
_________________
Rich

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

Ted · Posted: Thu Apr 15, 2010 10:42 pm Post subject:

Ahhh - there are no prohibitions for personal use Smile

I personally have it printed out and in a binder myself! When people want or need the info though I send them to ibmwr.org - the articles are frequently updated and on the rare occasion something is wrong it is taken down.

The thing that got me and others steamed was the PDF floating around that took all the content and omitted the names of the contributors and "IBMWR". The one on eBay was obvious, it had our names and e-mails and was passed off as a service manual -- for years I would occasionally get e-mail from people pissed off it was just a collection of articles and wanting their $30 back.
_________________

Ted

KOG#1