Page 1 of 2 1 2 LastLast
Results 1 to 15 of 27

Thread: 1987 K75S, tight valve.

  1. #1
    Registered User dieselyoda's Avatar
    Join Date
    Mar 2013
    Location
    Winnipeg, MB, Canada
    Posts
    543

    1987 K75S, tight valve.

    I'm doing some long needed TLC to a 1987 K75S with 67,000 miles that includes a good tune-up. Since it's bucket and shims for the valves, I thought a thorough check of clearances was all that was required.

    The specs I have for intake clearances is 0.006" to 0.008", a universal intake dimension. Bear with me, I am now comfortable the specs are accurate. I use a 0.006" feeler gauge as my "Go" and the 0.008" as my "no Go"

    I get to #1 intake and I'm a "no Go" at 0.006". I'm a "Go" at 0.003" but close to a "no Go" at 0.004" and definitely 0.005" won't go.

    This is the intake so I doubt I've got a cupped valve, compression and leak down were great. I'm now concerned I have a pulled stem.

    The question: Do I change the shim to gain clearance or do I assume I have a pulled stem?

    Next question: Do these engines drop valves?

    There are some engines I'd be yanking the head and replacing all the valves if I saw this because I know they drop valves. Camshaft lobes don't grow. Add a moderate amount of wear to the camshaft lobe, maybe 0.001" max without case harden break through, I'm thinking this engine is necking the stem by 0.002".

    I feel like I'm gambling with this one and the only place I gamble is Vegas and I know I will loose there most of the time. I don't want to gamble on this one.

    Then again, I might be the only person that ever checked and it's been like that from the assembly line...........

    Thoughts? They are very much appreciated.
    1997 R1100RT (Restored Basket Case) , 1981 KZ 440 LTD (Restored Basket Case)
    1986 K75S(the beutch), 1993 K1100RS (blown engine), 1997 Chev Short Box (4x4 with an LT1)
    "You can easily judge the character of a man by how he treats those who can do nothing for him."

  2. #2
    Registered User
    Join Date
    Mar 2008
    Location
    Belton Tx
    Posts
    593
    Change the shim. It is not uncommon for the intakes to tighten a little, however the exhausts have tightened more often on my 91 75RT. I would do all the valves and run it for 5000 miles or so and recheck.
    Ron

    91 K75RT ABS

  3. #3
    Registered User lkraus's Avatar
    Join Date
    Nov 2011
    Location
    Central Ohio
    Posts
    347
    Not a problem, change the shim. Valves and valve seats do wear with normal use causing the clearance to decrease.
    Larry
    2006 R1200RT

  4. #4
    Mars needs women! 35634's Avatar
    Join Date
    Apr 2008
    Location
    SW Ohio
    Posts
    2,010
    these engines rarely drop valves. They need so little care owners usually neglect checking them for 50k miles and then they might burn a tight exhaust valve.
    1987 K75S
    Original litter
    Original owner
    2012 Ural Gear Up

  5. #5
    3 Red Bricks
    Join Date
    Jan 2007
    Location
    Pleasanton, Ca.
    Posts
    3,336
    Yoda,


    It is kind of unusual to have an intake tighten up that much without the exhausts moving. Maybe the last person that was in there made a mistake in calculating the shim, went the wrong way, and didn't double check after the new shim was in.

    Since it is YOUR first time inside this particular bike, I would reset them so that YOU are sure that they are correct and see where things go in about 5k miles. Have not heard of any K75s dropping valves. I wouldn't worry.

    Shims come in approx. 002" (.05mm) increments.

    If you don't already have the shim tools or don't want to spring for the more expensive ones because you don't anticipate using them much, there used to be a guy that was making them. Don't know if he is still making them. You'd need to call or email him first to check. The quality was good for keeping a couple of bikes in shape for their life time. If you were going to make your living doing valve adjustments, you'd want the better ones. Kind of a Snap-on vs Harbor Freight kinda deal.

    Here's my comunication with him from 6 years ago:

    Hi Lee
    Yes, I have BMW "K" engine Valve Adj tools available for the 2 valve "K" engine.
    The 2 Pieces are made from 3/16? Laser cut steel. Working contours are identical to factory tools. Tools are new. Tools come w/ instruction sheet.
    $27 S/H included.
    Clutch pilots for K's are available also. New, from steel
    $18 S/H included.
    ?Pay Pal? to Polepenhollow, Cashiers Checks, Money Orders and Personal Checks accepted.
    I ship as soon as Pay Pal is posted or the check arrives.

    Thanks, Good Luck and Good Riding.
    Kenneth Lively
    318 S Hart St
    Palatine Il 60067

    polepenhollow@yahoo.com
    847-561-8555




    LONG MAY YOUR BRICK FLY!

    Ride Safe, Ride Far, Ride Often

    Lee Fulton Forum Moderator
    3 Marakesh Red K75Ss
    Mine, Hers, Spare

  6. #6
    Benchwrenching PGlaves's Avatar
    Join Date
    Oct 2003
    Location
    "Big Bend" TX
    Posts
    8,645
    I agree you need to get to a known base line. Without knowing the service history of the bike it is hard to tell what might be going on. My first K75 got one shim at 600 miles, and needed another (different valve) at 60K miles, then a third at 100K or so. It is possible that the seat moved a little and the valve hasn't been checked since that happened. In theory this settling in is all supposed to happen before the 600 mile service but; 1) it doesn't always happen that way, and 2) some frugal buyers neglect routine services.
    Paul Glaves - "Big Bend", Texas U.S.A
    "The greatest challenge to any thinker is stating the problem in a way that will allow a solution." - Bertrand Russell
    http://www.bigbend.net/users/glaves

  7. #7
    Registered User dieselyoda's Avatar
    Join Date
    Mar 2013
    Location
    Winnipeg, MB, Canada
    Posts
    543

    Thanks for the advice, I'm going to take it and run

    Bringing the valve clearances to a known good value and running awhile makes sense.

    Tight intake valves on most engines would make me nervous but if dropping valves on this engine isn't likely, a few thousand miles should tell me if I have a problem. That might be entire season on this bike.
    1997 R1100RT (Restored Basket Case) , 1981 KZ 440 LTD (Restored Basket Case)
    1986 K75S(the beutch), 1993 K1100RS (blown engine), 1997 Chev Short Box (4x4 with an LT1)
    "You can easily judge the character of a man by how he treats those who can do nothing for him."

  8. #8
    3 Red Bricks
    Join Date
    Jan 2007
    Location
    Pleasanton, Ca.
    Posts
    3,336
    Yoda,

    Your plan, good it is.


    02 11 12 1 460 622 GASKET (outer) 1 req. $8.51

    03 11 12 1 460 623 GASKET (inner) 1 req. $8.51


    05 11 12 1 460 368 PLUG (cam end) 2 req. $2.64 ea.


    06 11 14 1 460 934 BUSH (bolt) 10 req. $0.71 ea.



    While it is nice to replace all the valve cover gaskets at least once when you first get a 27 year old bike opened up, the two main gaskets and the two cam plug half moons will usually be reusable for MANY cycles of valve checks. The MOST critical is the rubber bolt bushings. The valve cover bolts bottom out (72-84 IN/lb) on the shoulder. It is the elasticity of the bushings that applies the clamping force to the gaskets. The bushings get hard and stiff from the heat and loose their clamping ability. If nothing else, try to replace those if they appear to be hardning.




    LONG MAY YOUR BRICK FLY!

    Ride Safe, Ride Far, Ride Often

    Lee Fulton Forum Moderator
    3 Marakesh Red K75Ss
    Mine, Hers, Spare

  9. #9
    Registered User dieselyoda's Avatar
    Join Date
    Mar 2013
    Location
    Winnipeg, MB, Canada
    Posts
    543

    Bought the consumables a month ago.

    I faced off the shim this afternoon, got a nice 0.0075" clearance, back together, will report if she blows!

    In my career, I wouldn't be comfortable with a tight intake but I don't make a living fixing motorcycles. I'm OK following the advice you have given here.
    1997 R1100RT (Restored Basket Case) , 1981 KZ 440 LTD (Restored Basket Case)
    1986 K75S(the beutch), 1993 K1100RS (blown engine), 1997 Chev Short Box (4x4 with an LT1)
    "You can easily judge the character of a man by how he treats those who can do nothing for him."

  10. #10
    MOA #24991 Pauls1150's Avatar
    Join Date
    Apr 2008
    Location
    south of Los Angeles
    Posts
    1,457
    Maybe I'm off base here, since I'm not a metallurgist, but aren't the shims surface-hardened?
    If a surface is milled (and is this the same as "faced off"?), you lose that hardening, and the shim will now wear more quickly.

  11. #11
    Registered User dieselyoda's Avatar
    Join Date
    Mar 2013
    Location
    Winnipeg, MB, Canada
    Posts
    543
    Quote Originally Posted by Pauls1150 View Post
    Maybe I'm off base here, since I'm not a metallurgist, but aren't the shims surface-hardened?
    If a surface is milled (and is this the same as "faced off"?), you lose that hardening, and the shim will now wear more quickly.
    To point, you are correct. Most case hardening is about 0.006" thick in my experiences. If I used a carbide cutter, not only is the cutter hard to control at the thickness I took off but generates a lot of heat which could damage the case hardening.

    I used diamond grit paste on a lapping wheel and let it go for several hours. I didn't have much choice as there is no exchange program for shims at my BMW dealer and they would only sell me a new one, which was a week away. There is another story there about how hard it is to deal with my dealership.

    If I had gone through the case hardening, I would have place the softer surface bucket side down and taken my chances.
    1997 R1100RT (Restored Basket Case) , 1981 KZ 440 LTD (Restored Basket Case)
    1986 K75S(the beutch), 1993 K1100RS (blown engine), 1997 Chev Short Box (4x4 with an LT1)
    "You can easily judge the character of a man by how he treats those who can do nothing for him."

  12. #12
    Still plays with trains. tinytrains's Avatar
    Join Date
    Oct 2009
    Location
    Torrance CA
    Posts
    494
    Shims are less that $5 each. I just keep the old ones in case I need it on a different valve.
    1988 K75 Low Seat
    2009 R1200R Roadster

  13. #13
    Registered User dieselyoda's Avatar
    Join Date
    Mar 2013
    Location
    Winnipeg, MB, Canada
    Posts
    543

    You don't know how lucky you are to have dealers close to you.

    Shims SHOULD be $7.20 NEW from the dealer. This dealer won't sell his "service" inventory and shims are not considered routine stock items and emergency supply only. The have an "engine down" policy for parts like this. I could have packed the bike up to them, completely assembled, determine the valve was tight and repaired it.

    Ready for this?

    The shim, special order, "engine down rush", ten days to supply, $52.00.

    The quote on repair, not to mention I have the bike in about two hundred pieces still and would have to trailer it as it needs to be safetied for licensing, just their quote, parts and labor, $680.00. They might be able to get to it in June if I brought it in right away.

    I am not exaggerating. They are the only dealer within an 800 mile radius. The closest other dealer to me is in Minneapolis or Saskatoon and the Saskatoon dealer is tiny.

    Where possible, I use the 'Net dealers.

    This dealer knows he is the only game in town.
    1997 R1100RT (Restored Basket Case) , 1981 KZ 440 LTD (Restored Basket Case)
    1986 K75S(the beutch), 1993 K1100RS (blown engine), 1997 Chev Short Box (4x4 with an LT1)
    "You can easily judge the character of a man by how he treats those who can do nothing for him."

  14. #14
    Registered User Paladinwest's Avatar
    Join Date
    Jun 2010
    Location
    BC South Central Interior
    Posts
    85
    I believe that there are some Japanese bikes that use the same diameter shim and that they can be interchanged. I haven't done it but if it is possible I am sure that someone else has.
    2008 HP2 Sport 10,000, 2008 R1200GSA 90,000, 1990 R100GSPD 100,000, 1986 K100RS 152,000

  15. #15
    Registered User Paladinwest's Avatar
    Join Date
    Jun 2010
    Location
    BC South Central Interior
    Posts
    85
    I believe that there are some Japanese bikes that use the same diameter shim and that they can be interchanged. See note from Internet BMW Riders website as follows:

    Yamaha/Kawasaki shims for 2-valve K shims

    Date: Tue, 18 Nov 1997 11:04:23 -0700 (MST)
    From: Tony Black

    One item did come up I want to let owners know about. If you need a shim for your 2 valve K and you don't have a dealer close by, shims from some models of Yamahas and Kawasakis will fit in the Ks. If you have one of these dealers closer I'd use them. I have many times on my bikes and others. Ciao Tony
    2008 HP2 Sport 10,000, 2008 R1200GSA 90,000, 1990 R100GSPD 100,000, 1986 K100RS 152,000

Posting Permissions

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