Results 1 to 9 of 9

Thread: borderline exhaust valve clearances

  1. #1
    Join Date
    Dec 2016
    Location
    Boston
    Posts
    107

    Default borderline exhaust valve clearances

    after re-assembling my '81 GS550T, five of thevalve clearances are clearly within spec, one is way out (.115mm for intake) and two are borderline.

    The borderline ones are both exhaust, one on the low side (.03mm) and one on the high side (.10mm).

    I'll adjust the .115 and .03 (too tight for exhaust in my book), but any input on the .10mm for exhaust?

    Thx
    Current rides: GS550T, CX500D, GL500, GL1100, Bonnie, Triumph Adventurer, Guzzi California

  2. #2
    Nessism's Avatar
    Nessism is offline Forum LongTimer GSResource Superstar
    Past Site Supporter
    Super Site Supporter
    Join Date
    Mar 2006
    Location
    Torrance, CA
    Posts
    33,710

    Default

    Error on the large clearance side. It's no problem running clearance up to .12mm. Tight on the other hand is NO GOOD.

  3. #3
    Join Date
    Dec 2016
    Location
    Boston
    Posts
    107

    Default

    Quote Originally Posted by Nessism View Post
    Error on the large clearance side. It's no problem running clearance up to .12mm. Tight on the other hand is NO GOOD.
    Thanks. I'll leave the .1 exhaust alone. INteresting the others are both on cyl3, .115 intake (too loose for me) and .03 exhaust (too tight)
    Current rides: GS550T, CX500D, GL500, GL1100, Bonnie, Triumph Adventurer, Guzzi California

  4. #4
    Join Date
    Jul 2013
    Location
    Wexford, Ireland
    Posts
    4,784

    Default

    Do you know what shims are on each valve?
    A simple swap could solve both exhausts if you are lucky.
    If it was just the .10 it would be safe enough to leave as is.
    80 GS850GT
    79 Z400B

  5. #5
    Join Date
    Dec 2016
    Location
    Boston
    Posts
    107

    Default

    Quote Originally Posted by Brendan W View Post
    Do you know what shims are on each valve?
    A simple swap could solve both exhausts if you are lucky.
    If it was just the .10 it would be safe enough to leave as is.
    I only addressed the extreme ones. With my collection of shims from past projects I was able to get all intakes between .04 and .1, and all exhausts between .06 and .1.

    Good enough for now.
    Current rides: GS550T, CX500D, GL500, GL1100, Bonnie, Triumph Adventurer, Guzzi California

  6. #6
    Join Date
    Jul 2013
    Location
    Wexford, Ireland
    Posts
    4,784

    Default

    Just a thought but I you keep a record of what shim thickness is where you can sometimes fix a clearance issue by swapping known shims.
    80 GS850GT
    79 Z400B

  7. #7
    Join Date
    Dec 2016
    Location
    Boston
    Posts
    107

    Default

    Quote Originally Posted by Brendan W View Post
    Just a thought but I you keep a record of what shim thickness is where you can sometimes fix a clearance issue by swapping known shims.
    Good point. I've done enough that it would also have to include shim diameter (25, 29, 29.5)
    Current rides: GS550T, CX500D, GL500, GL1100, Bonnie, Triumph Adventurer, Guzzi California

  8. #8
    Join Date
    Jul 2013
    Location
    Wexford, Ireland
    Posts
    4,784

    Default

    Have you got smaller than stock diameters on there?
    80 GS850GT
    79 Z400B

  9. #9
    Join Date
    Dec 2016
    Location
    Boston
    Posts
    107

    Default

    Quote Originally Posted by Brendan W View Post
    Have you got smaller than stock diameters on there?
    No, they are all the correct diameter. My total shim collection has multiple diameters because I have owned and resurrected numerous bikes over the years and different bikes/mfrs use different shim diameters.
    Current rides: GS550T, CX500D, GL500, GL1100, Bonnie, Triumph Adventurer, Guzzi California

Posting Permissions

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