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#1012979 - 06/13/18 10:51 PM Re: 1996 r1100rt issues [Re: Tracy B]  
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Posts: 33
Tracy B Offline
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Tracy B  Offline
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Posts: 33
West Bend, WI USA
Replaced spark plugs and tried syncing the throttle bodies. No matter what, one side read higher than the other. Couldn't get them to read anywhere close. Had both sides all the way down to end of threads and all the way loose, nothing.
Followed the instructions in the repair manual.
Help please! What am I doing wrong?


1996 BMW R1100RT, Red R1150RT fairings (supposed to be Glacier Green), factory heated grips and piaa lights.
#1012983 - 06/13/18 11:12 PM Re: 1996 r1100rt issues [Re: Tracy B]  
Joined: Jun 2010
Posts: 14,001
dirtrider Offline
The Oracle
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Ohio
Originally Posted by Tracy B
Replaced spark plugs and tried syncing the throttle bodies. No matter what, one side read higher than the other. Couldn't get them to read anywhere close. Had both sides all the way down to end of threads and all the way loose, nothing.
Followed the instructions in the repair manual.
Help please! What am I doing wrong?


Evening Tracy

What (exactly) did you have down to end of threads (the BBS screws or the cable adjusters?)

Are you having a problem syncing the idle (closed throttle) or above idle (part throttle?) or both?

If having an issue then first thing to do is remove the BBS air screws & clean the screw tips & the little passages down in the screw holes (use catalytic converter safe carb cleaner). You can't sync the curb idle with plugged passages or dirty BBS screw tips.

You also, absolutely, need to back the throttle cables off enough so both side throttle plate cams are resting tightly on the idle stop screws (a tight cable will make closed throttle plate syncing almost impossible)


D.R. ___
Sent from my rotory dial wall phone!
#1012984 - 06/13/18 11:32 PM Re: 1996 r1100rt issues [Re: Tracy B]  
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Posts: 33
Tracy B Offline
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Tracy B  Offline
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West Bend, WI USA
The cable adjuster lock nuts were all the way down on the threads. How do you get the cable adjusters to turn when lock nuts are loose? (In or out, couldn't get them to turn any direction)

Didn't remove the idle screws to clean them or the passageways, will try that tomorrow.

Syncing at idle and at part throttle.

It was suggested that I may have a vacuum leak as well. I will look into that tomorrow before I start trying to sync again.

The repair manual says to sync via the joining cable, that is the rear cable (when sitting next to bike on left side), is that correct?


1996 BMW R1100RT, Red R1150RT fairings (supposed to be Glacier Green), factory heated grips and piaa lights.
#1012988 - 06/13/18 11:51 PM Re: 1996 r1100rt issues [Re: Tracy B]  
Joined: Jun 2010
Posts: 14,001
dirtrider Offline
The Oracle
dirtrider  Offline
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Joined: Jun 2010
Posts: 14,001
Ohio
Evening Tracy B

The cable adjuster lock nuts were all the way down on the threads. How do you get the cable adjusters to turn when lock nuts are loose? (In or out, couldn't get them to turn any direction)-- Try some penetrating oil then use a small pair of pliers on the adjusters.

Didn't remove the idle screws to clean them or the passageways, will try that tomorrow. --Yes, those must be clean to get a decent idle balance.

Syncing at idle and at part throttle.--Good

It was suggested that I may have a vacuum leak as well. I will look into that tomorrow before I start trying to sync again.--On the BMW 1100/1150 boxers a vacuum leak usually gives a high idle speed so if it is idling at or near correct RPM's then no vacuum leak (or not enough to effect much anyhow). If the bike has a lot of miles on it then you will probably find a little vacuum leakage at the throttle shafts due to worn shafts & bushings. .

The repair manual says to sync via the joining cable, that is the rear cable (when sitting next to bike on left side), is that correct?--Depends!-- does your bike still have the original single cable system (no Bowden box?). If so then adjust using the crossover cable.

On the single cable (crossover cable systems) it is sometimes, or almost, impossible to get the curb idle balance, off-idle balance, & throttle plates to lift off idle stop screws at the EXACT same time. You want the off-idle (above idle) & throttle plate lifting off the stop screws at the same time to take precedence over idle balance as idle balance really isn't that important & you don't ride the bike at idle.




D.R. ___
Sent from my rotory dial wall phone!
#1012989 - 06/13/18 11:57 PM Re: 1996 r1100rt issues [Re: Tracy B]  
Joined: Sep 2016
Posts: 33
Tracy B Offline
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Tracy B  Offline
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Joined: Sep 2016
Posts: 33
West Bend, WI USA
My 1996 has 3 cables on the left side TB, from what i've read, it's the choke cable (inside front), main throttle cable (outside front), and joining/crossover cable (rear).

Thanks for the tip on the adjusters.

Things to work on tomorrow.


1996 BMW R1100RT, Red R1150RT fairings (supposed to be Glacier Green), factory heated grips and piaa lights.
#1012990 - 06/14/18 12:16 AM Re: 1996 r1100rt issues [Re: Tracy B]  
Joined: Jun 2010
Posts: 14,001
dirtrider Offline
The Oracle
dirtrider  Offline
The Oracle
Member

Joined: Jun 2010
Posts: 14,001
Ohio
Originally Posted by Tracy B
My 1996 has 3 cables on the left side TB, from what i've read, it's the choke cable (inside front), main throttle cable (outside front), and joining/crossover cable (rear).

Thanks for the tip on the adjusters.

Things to work on tomorrow.


Evening Tracy B

When it comes to the early 1100 single cable system (crossover cable system) you just about have to throw the book away as the book assumes the reader has done many before & is only using the book to look good to a customer.

On the single cable system NEVER adjust the cables or adjust the above idle balance after using the choke to start the engine as the choke cable pulls the main cable in the wrong direction on the L/H side cam so the cable works around the cam slightly. If adjusted after starting with the choke it will look & act balanced but will be off after the first ride as the main cable works it's way back to proper location. (if using the choke just before or during a TB balance always work the twist grip through full travel a few times before doing any cable adjusting).

The single cable system is not a tough nut to crack but sure is difficult for most first timers. Due to the single cable design one cable adjuster can effect the other cable runs & upset the entire process.

The cross side balance also changes as the lower (crossover cable heats up & expands from engine heat).

Persistence & patience are the key words when it comes to single cable systems.


D.R. ___
Sent from my rotory dial wall phone!
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