low compression

Results 1 to 5 of 5

Thread: low compression

  1. #1
    Bike
    bmw gs 650 2002 police model
    Join Date
    Apr 2020
    Location
    Caribbean
    Posts
    3
    Post Thanks / Like

    Default low compression

    Good day everyone, I have done a compression test on my bike a f650 gs 2002 and can only get 75 psi with no oil and 90 psi with some oil added ,I think I will remove the head and do a top end job . can someone help with a work shop manual ?

    egbert

  2. #2
    Bike
    GS/Gd Dakar 2003
    Join Date
    Oct 2008
    Location
    wakefield
    Posts
    1,633
    Post Thanks / Like

    Default

    Hi Egbert,
    plenty appear on eBay, copyright issues if some one points you to online version ?
    suggest check valve clearances first, may save your self some work,
    but sounds like rings/bore with oil increasing PSI,
    2003 GS Dakar
    BMW Panniers, top box, tank bag
    + loads TT stuff that came with it!

  3. #3
    Bike
    F650(1997) & F650GS(2000)
    Join Date
    Aug 2004
    Location
    Bedford.
    Posts
    823
    Post Thanks / Like

    Default

    do a leak down test should point to problem , -- rings or valves , gsk . before taking apart.
    If there is one.
    Last edited by anthony; 11-05-2020 at 07:16 AM.

  4. Remove Advertisements
    F650.co.uk
    Advertisements
     

  5. #4
    Join Date
    Apr 2019
    Posts
    471
    Post Thanks / Like

    Default

    Quote Originally Posted by pol650 View Post
    Good day everyone, I have done a compression test on my bike a f650 gs 2002 and can only get 75 psi with no oil and 90 psi with some oil added ,I think I will remove the head and do a top end job . can someone help with a work shop manual ?

    egbert
    The problem doing a compression test on an F650GS is that it is fitted with an auto compressor which reduces the pressure in the cylinder on start up. It's possible your measured pressures are ok. Before going too far, I would take off the valve cover, remove the decompressor and then try the test again. If you then get less than 150-180 psi, a top end overhaul is probably required.
    2006 F650GS in Black
    9,300 Miles

  6. LikesLOL GEOFF liked this post
  7. #5
    Join Date
    Dec 2003
    Location
    Hartley, Kent (59 XT660Z Tenere)
    Posts
    183
    Post Thanks / Like

    Default

    Also make sure you have the throttle wide open too.


Posting Permissions

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