20k Valve adjustment necessary?

Discussion in 'Parallel Universe' started by selecus, Sep 21, 2011.

  1. selecus

    selecus --------

    Joined:
    Jun 24, 2008
    Oddometer:
    80
    Location:
    Montreal
    Hey Gang,

    I currently have about 14k kms on the bike, I'm heading south to TDF from Montreal in a couple weeks, by the time I get to Houston I'll be approaching 20K kms, wondering if I should bother with the valve adjustment service before I cross into Mexico.

    On previous bikes, every time I've brought it in for valve adjustment, everything has been fine, no adjustment was necessary...usually money well wasted. So I'm wondering how many of you brought the 8GS in and it actually needed adjustment. Money is tight for the trip, so I could obviously do without the expense...

    Thanks!
    #1
  2. reinerka

    reinerka Been here awhile

    Joined:
    Oct 5, 2004
    Oddometer:
    350
    I'm now at 40K miles and have yet to adjust a single valve.

    Shim under bucket don't wear that easily (read adjustments are rare) but not unheared off. For piece of mind I would still have them do the check for piece of mind. Nothing can be worse on such a trip than to worry if you did the right thing. It's like leaving with worn out tires and not being sure they carry you home again.

    On our GL1800 (same shim design) it took about 70K miles until the first adjustment was needed. Then it was almost like a recurring theme as in the course of the next 50K miles EVERY shim needed to be changed (12 total). The process would recurr after about another 70K miles.....

    Reiner
    #2
  3. Camel ADV

    Camel ADV Long timer

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    YES, CHECK THE VALVES!

    You're at 14,000km now, Montreal to TDF is 30,000km-ish so 44,000km without at least checking them is taking a big chance. If money is tight enough that you're concerned about the couple hundred to get the clearances checked/adjusted then dealing with a motor that needs a complete head overhaul due to burnt valves is definitely going to stress your budget!

    Also, if you need shims, they will likely be easier/faster to get in North America than at a dealer farther into your trip.

    Check them yourself if you're really worried about spending the money.

    Step by step valve adjustment

    Cory
    #3
  4. ScienceOfDirt

    ScienceOfDirt U-Boat Rider

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    Have them put the valves in the center of the tolerance if you have them checked even if they're in spec. That puts you furthest from trouble in my book.
    #4
  5. selecus

    selecus --------

    Joined:
    Jun 24, 2008
    Oddometer:
    80
    Location:
    Montreal
    Well guess that settles it, I'll get it done, thanks for your input everyone...
    #5
  6. MikeMike

    MikeMike Long timer

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    Feb 28, 2009
    Oddometer:
    4,150
    Local dealer here quotes at least a two week wait for shims as they don't stock them, imagine that.
    Now you know why I get so "encabronado" with them.
    #6
  7. TheCowboy

    TheCowboy back in the saddle again

    Joined:
    Feb 15, 2008
    Oddometer:
    611
    Location:
    The frozen tundra - Minny Sota
    50,000+ miles - no valve adjustments... she is running just fine and I have no plans to do a valve adjustment just yet... hey, just sayin....

    TheCowboy
    #7
  8. FredRydr

    FredRydr Danger: Keep Back 500 Ft.

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    Shims could be overnighted from the distribution center for the cost of a flat-rate envelope. Doesn't make sense. Someone's being lazy.

    Fred
    #8
  9. Camel ADV

    Camel ADV Long timer

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    No one said an adjustment would be required. I'm at 67,000km and haven't had any out of spec but I still check them every 15,000-20,000km.

    Mike is in Mexico.
    #9
  10. reinerka

    reinerka Been here awhile

    Joined:
    Oct 5, 2004
    Oddometer:
    350
    That is strange, unless they have yet to adjust a bike. Normally dealers would keep the old shims and use them on another bike when needed as the shims don't really wear out.

    When I used to need shims for the GoldWing I walked to the service department (not the parts department) and got what I needed immediately (they didn't stock any shims in the parts department). If I would have swapped the shims they would have given them for free (not the $8 they normally cost). They had all sizes in abundance....

    Reiner
    #10
  11. uraberg

    uraberg whosaberg?

    Joined:
    Apr 21, 2009
    Oddometer:
    707
    Location:
    Buffalo, NY
    You may want to reconsider this. Since normal wear will always decrease the valve clearance, setting the clearance at the wide end of spec is a better way to go. Really, only carbon buildup may increase the valve clearance, but this usually manifests with noticeable power loss, and is not necessarily harmful to components. Running zero clearance is where you start to see real damage.
    #11
  12. bumbee800

    bumbee800 Adventurer

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    What are you basing that logic on?:hmmmmm

    Most every overhead cam engine the wear is between valve rocker arm and cam lobes. This wear will cause the valve clearance to increase with wear rather than decrease. As the wear in the valve train removes metal from the cam lobes and the rocker arm follower the shims will need to increase in thickness to keep the valve clearance in specification.

    The only way the valve clearance can decrease is if the valve is forced up into valve seat. If this is happening then you have a bigger problem as this will dictate you removing the head and replacing the valve seats as the valve seats should be made of hard enough material to prevent the valve from being forced upwards.
    #12
  13. MikeMike

    MikeMike Long timer

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    Oddometer:
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    That is at a normal dealership. I have a suspicion that they have yet to actually adjust the valves on an F800 or 650 at this local dealership. Yes, they can do a check with a simple "go/no go" method like they were supposed to have done on my F650 at the 20k service. However, when I asked them what the measurements were they had no idea what I was talking about. I told them that if they measured each valve clearance they should have recorded it as a service to the customer and noted the measurements on the service order. They told me they have never done that. The chief mechanic has not completed his factory training and has a gaggle of wannabees working with him. I am now going to use another dealer for service but it is a 400km ride and I will only use them if absolutely necessary.
    My bike is out of warranty (though they didn't honor many claims I had but that is another story), a friend of mine has the same bike but with more miles so we are going to do his valve check first. If they need adjusting, he will probably take it to the dealer 400kms away for that. BMW service appears to vary from the sublime to the ridiculous throughout the world and I am unfortunately stuck with a dealer at the wrong end of that linear measure!
    #13
  14. itsatdm

    itsatdm Long timer

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    These are not a shim on bucket or shim under bucket valve system. This is a conical "shim cap" that fits on top of the valve stem. The cam lobe connects to a following lever connected to the valve stem
    Typically any wear tightens the valve clearance. I do not know how much wear occurs to the "cap" an I doubt they are measured and saved. They are cheap and would not bother with discards. I thought it important enough to have the dealer to do them to ensure warranty problems, though ther has been very little wear reported.
    #14
  15. vtbob

    vtbob wanderer

    Joined:
    Jun 20, 2009
    Oddometer:
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    Location:
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    FWIW I has my 12000mile/20k service done and the valves needed no adjustment.

    The cost is getting to the valves to check them...doing to soon is clearly a waste of money IMHO

    I would not worry about your trip...do it Save the money and get it done when you get back

    enjoy

    ps the dealer said doing the next check at 24000 miles/40 is the proper interval
    #15
  16. bumbee800

    bumbee800 Adventurer

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    One end of the follower pivots on a shaft and the other end of the follower rest on top the valve stem. The cam lobe pushes down on the follower at some point in between the pivot and the valve stem. There fore you have 3 contact points. The pivot point that should never move, the cam lobe to follower and then the follower to the adjuster cap sitting on top the valve stem. The pivot point just rotates on a bearing and has very slow wear rate so take that out of the mix, The cam lobe to follower is metal to metal contact so it will wear only increasing valve clearance. The valve adjusting cap contacting the follower is metal to metal contact so it will wear only increasing valve clearance. The only way valve clearance can decrease is if something increases in length or grows in diameter and there is no way anything in this entire valve train increases in diameter or length they only decrease. There fore the valve clearance can only increase not decrease. The only possible way the valve clearance can increase is if the valve is pushed up further into the valve seat causing the valve stem to push up further into the valve train. Again if this is happening no adjustment in valve clearance will remedy that problem, the only fix is to put in harder valve seats.
    #16
  17. Snowy

    Snowy Long timer

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    2,390
    Bucket and shim???

    facepalm

    I swore I'd never buy another bike with bucket and shim adjustment again......


    Time to trade.




    Conical cap/bucket and shim......it aint locknut and screw. Therefore, it's a dickaround.
    #17
  18. itsatdm

    itsatdm Long timer

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    Nor Ca.

    I have been doing my own valve checks for the last 14 years on two bikes with bucket and shim. 14 valves, 90,000 miles with numerous shim replacements and my experience has been different. Just did the first one on a KLX that had a recent upper end job, including the seats. Same story.

    The 800 is not your typical bucket and shim design. Perhaps it should be called lever and cap. The warranty is up, so I will be doing my first on the bike and maybe your theory will be correct.
    #18
  19. MikeMike

    MikeMike Long timer

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    You lost me there. Do you mean to say "The only possible way the valve clearance can DECREASE (instead of "increase") in the second sentence above?
    #19
  20. Dieselboy

    Dieselboy Journey not Destination

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    I am a rock when it comes to understanding how these things work, but at 88,000 miles two valves were too loose out of spec and were re-shimmed to bring them back in. This was the first time an adjustment had been made in the life of this machine which had been dealer maintained up to 36,000 miles. After 36k I figured it was good to go for a substantial amount of time, and I was correct. So as opposed to my R bikes, this F appears to get loose instead of tight. Is that normal? No idea. But just to comment on the OP's question, I wouldn't obsess over the valves with only 20k.
    #20