Throttle Body Problems

Discussion in 'GS Boxers' started by bigtodd, Apr 25, 2013.

  1. Tuff Tunica

    Tuff Tunica Moto-Skiveez creator

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    How difficult was it to get the shaft out of the TB once you removed the butterfly valve? Did you have to open the other side with the round metal button cap? Or did the shaft pull out easily? I've got a hairline crack in the right TB. I used some JB weld and the freeze cap mentioned in your earlier post for a quick fix. I'd really like to get the machined cams from Beemer Bits but at $450 a pair I may have to wait. $104 for new shafts and pulleys may have to do. I could replace and then keep the originals as spares. This is, of course, assuming that replacing the shafts is not that difficult. Thank you in advance.
  2. DKW1200

    DKW1200 Been here awhile

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    You can sent the TB’s to Motoghost in Phoenix and they do a professional rebuilt. I’ve been very happy with all their work.
  3. manybike

    manybike Omnipresent

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    what is the ballpark cost of them doing the rebuild ?
  4. Tuff Tunica

    Tuff Tunica Moto-Skiveez creator

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    $450 for the two throttle cams and $145 for the install. Much less expensive than two new throttle bodies. I'm leaving Feb. 3 for a week in Baja on my 2007 GS Adv. Just want to know that I will not have this concern while I'm down there. I'm very happy to do the install. I feel confident about my ability to do it after watching their video. It's just the $450 for the two cams that I'm hoping to avoid. My cams are not cracked at this time, but I intend to keep the bike for quite a while longer and I'd just like to have the peace of mind that won't occur. If I can find a competent adhesive, I think that gluing the freezer plug as a support cover will ease my mind. Especially if I do it to two totally new cams. $104 plus some glue and caps is a lot easier to swallow.
  5. Mcgee

    Mcgee Been here awhile Supporter

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    I have an 09 GSA that has quite a few miles on her. I'm concerned about the throttle cams before taking a long trip this summer. I read that you could remove the plastic covers and inspect them while still on the bike. How does the cover come off? I see a clip and looks difficult to get to. Does anybody have any ideas for the inspection? Thanks for responding!
  6. AKjeff

    AKjeff Long timer

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    I need to clean my throttle bodies, I have a cold stumble off idle.
    I may just order up new plastic bits and install them while I'm at it to try and stay ahead of things.
  7. BluByU

    BluByU Been here awhile

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    Where can I order the plastic throttle cams,
    Just too dam lazy to read through this entire thread
  8. Tuff Tunica

    Tuff Tunica Moto-Skiveez creator

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    Yes, there is just a single plastic clip on the inside section of the cover that if you release, then you can slide the cover up the cable and use a mirror to examine. Fairly straight forward.
  9. Tuff Tunica

    Tuff Tunica Moto-Skiveez creator

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    So here's my "nickel fix" for the cam cracking. My discovery of this issue stemmed from doing a throttle body sync and noticing that the cable to my right throttle body was loose. The attachment that holds the cable to the TB was cracked. In trying to locate just this replacement piece, I learned about the cam issues. Well, sure enough, my cam had a minor crack in it. I would most likely not have even noticed this.

    Back to my original issue... I attempted to JP Weld the attachment bracket, but this bracket is what the cover clips to, so the additional adhesive prevented the cover from latching. In addition, my repair did not work in that there is a very small inner section that had cracked and I could not get adhesive to, (see the bottom of image).
    IMG_3818.JPG
    This resulted in me ordering two bodies off of eBay. I figured I'd just replace the right body and be done with it. Alas, when the new bodies arrived, the bracket to hold the cable was fine but the cams were significantly cracked.

    IMG_3820.JPG
    My idea now is to transfer the cable attachment from the eBay TB to my TB. Which I did. This resulted in the idle adjustment screw no longer being in sync with the cam. I know it is a mortal sin to adjust this screw, but I had no option. I very carefully measured any space between the screw and the cam on original TB with feeler gauges, there was no clearance. Then examined as closely as possible the position of the butterfly valve in the TB. I reattached the eBay TB cable bracket to original TB then adjusted the idle screw to match as closely as possible to what I determined to be the setting on my original TB. Sorry I did not take any photos of this process. Hold breath...cross fingers...


    Now to address the crack in my cam. The plastic that the cam and bracket are made from is polyoxymethylene or POM. I've read that literally no adhesive will attach to it. Well, at least not well. There was mention in an earlier post about attaching a washer to the plastic, I thought that if I could get adhesive on the inner part of the cam where there is metal, this will adhere.

    IMG_3819.JPG
    And, if I can attach something to this area of adhesion it should offer significant reinforcement. Similar to the freeze plug repair mentioned earlier. In addition, I know from my earlier attempt to repair the cable bracket, that JP Weld does hold quite well to POM. I wanted something in very close diameter that would not rust. A nickel proved to be just the ticket. I sanded the plastic well, then filed flat one side of the nickel, prepped everything by cleaning with acetone, then glued the nickel to the JB Weld.....ta da!

    IMG_3821.JPG
    Callisto224 likes this.
  10. Tuff Tunica

    Tuff Tunica Moto-Skiveez creator

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    I did all of this two days ago. I have since taken off my opposite TB to examine and sure enough, it too had a small crack. Same repair to it. I feel much more at ease knowing that, although my cracks were only slight, this should be enough to prevent total failure. I know that the inner metal part of the cam should adhere well to the JB and the full surface area of the nickel.

    If/when the funds become available, I will most likely opt for the Beemer Bits machined cams. I like knowing that their's is a permanent solution with literally no risk of failure. But for now, this puts my mind at ease.

    Side view of the "nickel fix."
    IMG_3822.JPG

    Oh, and after a test ride, having totally adjusted the "DO NOT EVER, UNDER ANY CIRCUMSTANCE, FEAR OF DEATH" warnings about adjusting the idle adjustment screw, I can say that my bike has never run better! Maybe I just got lucky, but coming from a bike that was getting 36-38 mpg and in dire need of a tune-up. After a shakedown, very spirited ride yesterday with a lunatic buddy on his 990 KTM my bike was getting 43.5 mpg! At best, under anemic riding prior to this, I could get 42-44 mpg. In addition, I have no popping under deceleration with a full AKRO exhaust, which I always had, and the bike has never felt more responsive. I should also mention that while I had the TB's off, I gave them a very thorough cleaning. So there you have it. My opinion is that YES you can touch the idle adjustment screw, and the "nickel fix" may just be a quick solution for a minor repair of a cracked TB cam.
    Callisto224 likes this.
  11. Mcgee

    Mcgee Been here awhile Supporter

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    Thanks for that advice! It's nice to hear that it can be done without opening a can of worms. I will take a look.
  12. Mcgee

    Mcgee Been here awhile Supporter

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    09 GSA.
    Well, after inspection, yep they were cracked. Decided to change the cams and shafts bought from Bing in Kansas. did this for peace of mind for the up and coming riding season and some long trips planned. After talking with the rep he said he would also send some nylon bushing that go around the springs and some extra little clips for the end of the throttle shafts. Very nice quality.
    After installing them it seems to be running pretty rough at the idle. Moved the cable adjuster up on the left side to bring up the idle, then brought it down a full turn to make sure there was slack. Then to the right side where it seems that I cannot get the idle to raise, so brought the adjuster down and commenced to sync the bodies at around 3500 rpm. All seems well at speed, smooth and good power running up hard. At idle and a bit above it wants to stall and has some purging going on.
    I did check for the seal around the rubber boots and all is good there. Also checked to make sure the cables were seated on the Bowden box. Not sure what else to do except find a GS911 and sync stepper motors then go from there. Any ideas? The bike ran great before this change.

    Attached Files:

  13. BluByU

    BluByU Been here awhile

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    Mr Mcgee, do you have a contact at Bing? If so please PM me with a number or E-mail. I would love to get a set of the cams and shafts
  14. edorfox

    edorfox n00b

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  15. Mcgee

    Mcgee Been here awhile Supporter

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    I installed new throttle shafts and cams on my 09, now I can't get the idle to balance. Stepper motors. I think with the new cams, the discs or plates are not in the same location as the original ones and are out of whack. They do stop on the idle stops just fine and idle is a good rpm, just won't balance. The rest of the sync is just fine and runs good at speed. No leaks at the boots or any of that stuff. Double checked the throttle plates for correct orientation. Has anyone else had this problem with the new shafts from Bing? Thank you for your reply.
  16. edorfox

    edorfox n00b

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    Perhaps, with the new positioning of the throttle plates (as it's probably impossible to put them back in virtually the same spot as before) you may end up needing to adjust the blue sealed adjustment screws...you know...the ones we're never supposed to touch. :yikes Unless there is some sort of vacuum leakage via the shaft bores or the easily missed cable routing or slack adjustment, I can see the blue screw adjustment as a possibility. Here are a couple threads from competing forums than may shed additional light on your journey... https://forums.bmwmoa.org/showthread.php?17496-R1200-series-Throttle-Body-Sync-Pictorial and, https://forums.bmwmoa.org/showthread.php?48397-Setting-throttle-stop-screws ...PLEASE don't take this as a recommendation, just a thread for more info.

    Ed
  17. Mcgee

    Mcgee Been here awhile Supporter

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    Thanks Ed for the info. I was thinking that since I did replace the cams and shafts and not paying attention to the new ones from Bing, if they were EXACTLY the same as the original ones that there might have to be an adjustment. The steppers not being able to get it into sync. Like I said, the idle is good, just bad balance at idle. In other words, one plate is off by a hair. Like I said, the cams are on the idle stops just fine. I'm kinda reluctant to mess with the screws. Maybe put the old ones back and live with it.:(
  18. edorfox

    edorfox n00b

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    Well, the screws can be adjusted and if required, returned to the exact previous position if you do it in precise documented movements. Just a thought.

    Ed
  19. JimVonBaden

    JimVonBaden "Cool" Aid! Supporter

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    On the Hexhead/Camhead you will never see a balance at idle. If you try you will fail. Just do a stepper motor calibration and an off idle calibration and call it good. The computer controls idle via the stepper motors.
    Mcgee likes this.
  20. Mcgee

    Mcgee Been here awhile Supporter

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    Thanks Jim, I'm coming to the conclusion that the new shafts and cams are a bit different. Just to get the slack in the cables uses up all the adjustment. The locking nut and the adjusting nut are almost touching.
    The stepper motor calibration isn't working either. I'm going to pull them off again and take a closer look at the cams and do a comparison as I should have in the first place.:doh