Results 1 to 9 of 9

Thread: vaccum pipes

  1. #1
    jimmy armour
    Join Date
    Jul 2009
    Location
    Lucknow ontario canada
    Posts
    272

    vaccum pipes

    Hi again guys , I,d like to wish seabecks all the best for the future, after 53 years riding all sorts of bikes and 43 of these years riding BMW,s I too can see the last long rides coming hopefully in a few years, this new to me 2000 r1100 rt is my last kick at the can, my son will take over my 1977 r100s, so I will not be riding alone, over the years I have met and befriended a lot of interesting people, my close riding buddies have all pasted on ,as I was the youngest,now 69, once again I wish you all the best, now to my question,my rt has had the charcole filter removed and still has the cross over pipe from the throttle bodies attached I note on a U tube video that a gs has just these blanked off ,is there a difference ? as always thanks in advance Jimmy

  2. #2
    Registered User jagarra's Avatar
    Join Date
    Aug 2016
    Location
    Reno, NV
    Posts
    249
    When I did my Canisterectomy I left the cross over pipes between the throttle bodies on, I just capped it off at the T. When I first did it, I removed the crossover pipe and capped off the TB individually, I noticed some differences in running smoothness, so I installed the cross over back and just capped it.
    1994 R1100RS-(5/93)-,1974 R90/6 built 9/73,--1964 Triumph T100--1986 Concours

  3. #3
    jimmy armour
    Join Date
    Jul 2009
    Location
    Lucknow ontario canada
    Posts
    272

    just what I thought

    thanks for the very quick responce, yes thats what I thought might happen ,so will leave well enough alone thanks again Jimmy

  4. #4
    MOA #24991 Pauls1150's Avatar
    Join Date
    Apr 2008
    Location
    south of Los Angeles
    Posts
    2,272
    If the throttle bodies are perfectly adjusted, there "should be" no difference, since the intake vacuums would be equal, though happening at different times in the crank's rotation. But nothing is perfect, and things change over time, like stretching cables. If there is a difference, they can be more carefully sync'd.

    I have my ports closed off with properly-fitting caps (and little red tie-wraps just to make sure they don't disappear). My bike runs great.

    Why leave the balance hose on at all? It's just another place to potentially leak (suck air) in the future.

  5. #5
    Registered User jagarra's Avatar
    Join Date
    Aug 2016
    Location
    Reno, NV
    Posts
    249
    Well after I had them individually capped off I noticed a different pulsing/vibration via the seat of my pants. So I figured something in the Canisterectomy was the cause. First thing I did was when I returned from my ride was to put the TB sync unit back on there to see if anything changed, nope. Throttle cable is new style for 1100. I went back to coupling the TB again via that vacuum line.
    1994 R1100RS-(5/93)-,1974 R90/6 built 9/73,--1964 Triumph T100--1986 Concours

  6. #6
    Day Dreaming ... happy wanderer's Avatar
    Join Date
    Mar 2010
    Location
    Vancouver, B.C. Canada
    Posts
    2,603
    Before there were cannisters and on models that had no canisters like the early 1100 Euro/CDN models the throttle bodies were simply capped off. There was no balance line between them and it is not needed IMO.

    Near to perfect as you can get valve adjustment and careful TB balance adjustment at idle and 3 to 4K RPM is what is required to get a vibration free oilhead. The throttle cables need to be clean and in good condition as well as the pulleys on the throttle bodies being spanky clean with NO vacuum leaks at the TB bushings or intake rubbers.

    If it surges or "hunts" as some call it then you have an overly lean mixture and the fix for that is the AF-XIED or an LC2 from Innovate Motorsports. Tons of stuff has been written here on this subject.
    MJM - BeeCeeBeemers Motorcycle Club Vancouver B.C.
    '81 R80G/S, '82 R100RS, '00 R1100RT

  7. #7
    Registered User bewareboy's Avatar
    Join Date
    Sep 2015
    Location
    Cincinnati, OH
    Posts
    18
    Quote Originally Posted by happy wanderer View Post
    Before there were cannisters and on models that had no canisters like the early 1100 Euro/CDN models the throttle bodies were simply capped off. There was no balance line between them and it is not needed IMO.

    Near to perfect as you can get valve adjustment and careful TB balance adjustment at idle and 3 to 4K RPM is what is required to get a vibration free oilhead. The throttle cables need to be clean and in good condition as well as the pulleys on the throttle bodies being spanky clean with NO vacuum leaks at the TB bushings or intake rubbers.

    If it surges or "hunts" as some call it then you have an overly lean mixture and the fix for that is the AF-XIED or an LC2 from Innovate Motorsports. Tons of stuff has been written here on this subject.
    Happy Wanderer,

    When you talk about vacuum leaks at the "intake rubbers", is that the rubber joint between the front of the throttle body and the intake port on the cylinder? If not, can you explain where this location is? How common is it for the "intake rubbers" to leak?

    Thanks,
    Jim "BewareBoy" Snyder
    Cincinnati, OH
    2004 R1150RT

  8. #8
    MOA #24991 Pauls1150's Avatar
    Join Date
    Apr 2008
    Location
    south of Los Angeles
    Posts
    2,272
    Yes; they're also called "inlet manifolds". They sometimes get damaged from somebody over-tightening the clamps or mounting screws, sometimes they just crack with age. The cracks may only be "surface" damage, but if the crack is on the inside, that's a leak, and you can't see it unless you pull the throttle body and shine a flashlight down there.

    BMW is not the only manufacturer who's had this problem.

    BTW, I do my cable balance at about 2500 RPM - the difference between the two sides decreases as RPM increases, so at lower RPM, it's easier to see on the vacuum gauge. It's pretty important that, if you use a differential meter, the Zero and Sensitivity settings are actually correct; it's also important that the valves are set (cold!) properly (which to me means a hair looser than "spec").

  9. #9
    Day Dreaming ... happy wanderer's Avatar
    Join Date
    Mar 2010
    Location
    Vancouver, B.C. Canada
    Posts
    2,603
    Quote Originally Posted by bewareboy View Post
    Happy Wanderer,

    When you talk about vacuum leaks at the "intake rubbers", is that the rubber joint between the front of the throttle body and the intake port on the cylinder? If not, can you explain where this location is? How common is it for the "intake rubbers" to leak?

    Thanks,
    Late reply. Stopped raining for a day up here so I had to go riding!
    Pauls1150 posted the correct term for the "inlet manifolds". I keep using old airhead terminology for oilheads. I should have said the seal between the front of the throttle body to the head intake or some such.

    Sorry for the confusion but yeah, they have been known to leak. Finding the leak with WD40 sprayed all over the place while the bike is idling sometimes works as it can cause the idle RPM to go up from ingesting the solvent and burning it.
    MJM - BeeCeeBeemers Motorcycle Club Vancouver B.C.
    '81 R80G/S, '82 R100RS, '00 R1100RT

Similar Threads

  1. Help! Plastic on pipes!
    By rogert in forum Oilheads
    Replies: 11
    Last Post: 10-24-2008, 11:56 PM
  2. What do your pipes smell like?
    By tonkandy in forum Campfire
    Replies: 13
    Last Post: 03-14-2008, 04:47 AM
  3. vaccum or potatoe?
    By redclfco in forum Campfire
    Replies: 22
    Last Post: 01-08-2008, 06:10 PM
  4. Y pipes
    By Jfixit in forum Oilheads
    Replies: 3
    Last Post: 01-18-2007, 04:56 AM
  5. Vaccum in crankcase?
    By basketcase in forum Flying Brick K-bikes
    Replies: 5
    Last Post: 01-25-2004, 12:14 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •