First DIY Valve Clearance Check

Discussion in 'Mechanics Garage' started by MiddleTBabb, Jan 16, 2012.

  1. MiddleTBabb

    MiddleTBabb New Member

    Country:
    United States
    Joined:
    Nov 10, 2007
    Messages:
    775
    Likes Received:
    1
    Trophy Points:
    33
    Location:
    Murfreesboro, TN
    Map
    So,

    after getting the bike running a year ago and enjoying it for a season, I wanted to check the valves myself. I'm using a Honda service manual.

    I'm stuck. The correct feeler gauge won't fit between any of the cam lobes (intake or exhaust) on piston #1 and I'm 95% sure that the engine is in the right placement. (see pics below)

    Thoughts? Am I looking a the wrong piston? I think not because the manual tells me that #1 is the rear left piston (from the rider's position when seated on the bike)

    Also, if there is no clearance at all, which direction do the adjustment screws need to rotate? Clockwise or CCW?

    A recent compression test got somewhere around 130 psi for each piston

    thanks in advance

    [​IMG]

    [​IMG]
     
    MiddleTBabb, Jan 16, 2012


    This site may contain affiliate links for which VFRworld may be compensated
    #1
  2. tinkerinWstuff

    tinkerinWstuff Administrator Staff Member

    Country:
    United States
    Joined:
    Oct 5, 2009
    Messages:
    7,831
    Likes Received:
    91
    Trophy Points:
    78
    Location:
    Colorado Front Range
    Map
    you said the "correct" gauge doesn't fit...

    which gauge "does" pass thru?

    right or wrong, I worry less about having the engine in exactly the correct location per the book. I just observe the cam lobe on the valves I'm checking and make sure that the lobe is pointing away from the valve. The low side of the lobe "should" be the same all the way around until it lifts.

    The issue is - if an adjustment is required, then it's critical to have the crank and cam reference points all in the correct location per the book. That way when you pull the cam, you can get it back in the right timing.

    So I run through all the valves and write down what they measure. Just rotating the motor until the lobes are clear. Once I have all the actual measurements documented, I can figure out which need to be adjusted and how much. Rotate the motor to align the timing marks, pull cam, make adjustments on any and all valves for that cam. Reinstall, rotate and remeasure. If your math is good, should be good to go!
     
    tinkerinWstuff, Jan 16, 2012


    This site may contain affiliate links for which VFRworld may be compensated
    #2
  3. Lgn001

    Lgn001 Member

    Country:
    United States
    Joined:
    Nov 11, 2007
    Messages:
    1,855
    Likes Received:
    1
    Trophy Points:
    53
    Location:
    Russian River by Ocean, CA
    Map
    Based on the top picture, it looks like the lobes are partially (or close to) lifting the valves. Like Tink said, rotate the engine until the lobes are roughly opposite the valves. I generally shoot for 180 degrees opposite, as in the lobes pointing straight up as referenced to the valve stems, but 25 degrees or so in either direction off center will probably be fine. I'm assuming this is your '86 since you reference screw adjusters. I've never worked on one, so I can't offer any input on which way they need to turn. Are they located behind the cam housing in the picture?
     
    Lgn001, Jan 16, 2012


    This site may contain affiliate links for which VFRworld may be compensated
    #3
  4. MiddleTBabb

    MiddleTBabb New Member

    Country:
    United States
    Joined:
    Nov 10, 2007
    Messages:
    775
    Likes Received:
    1
    Trophy Points:
    33
    Location:
    Murfreesboro, TN
    Map

    The service manual says intake should have 0.004 thru 0.005 inches of clearance, the one i used was 0.004 thru 0.006
     
    MiddleTBabb, Jan 16, 2012


    This site may contain affiliate links for which VFRworld may be compensated
    #4
  5. TOE CUTTER

    TOE CUTTER Mullet Man

    Country:
    United States
    Joined:
    Nov 30, 2008
    Messages:
    6,731
    Likes Received:
    86
    Trophy Points:
    78
    Location:
    Sacramento
    Map
    It does look like you have the engine 180 oot.
     
    TOE CUTTER, Jan 16, 2012


    This site may contain affiliate links for which VFRworld may be compensated
    #5
  6. MiddleTBabb

    MiddleTBabb New Member

    Country:
    United States
    Joined:
    Nov 10, 2007
    Messages:
    775
    Likes Received:
    1
    Trophy Points:
    33
    Location:
    Murfreesboro, TN
    Map

    yes they are on the other side of the cam:

    [​IMG]
     
    MiddleTBabb, Jan 16, 2012


    This site may contain affiliate links for which VFRworld may be compensated
    #6
  7. MiddleTBabb

    MiddleTBabb New Member

    Country:
    United States
    Joined:
    Nov 10, 2007
    Messages:
    775
    Likes Received:
    1
    Trophy Points:
    33
    Location:
    Murfreesboro, TN
    Map
    I have some time this afternoon and I'm going to mess with it more. thanks a million for the timely input updates to come
     
    MiddleTBabb, Jan 16, 2012


    This site may contain affiliate links for which VFRworld may be compensated
    #7
  8. tinkerinWstuff

    tinkerinWstuff Administrator Staff Member

    Country:
    United States
    Joined:
    Oct 5, 2009
    Messages:
    7,831
    Likes Received:
    91
    Trophy Points:
    78
    Location:
    Colorado Front Range
    Map
    :doh: I was missing the fact that this was a tappet and rocker adjuster vs. shim/bucket adjustment. Sorry if there was any confusion.
     
    tinkerinWstuff, Jan 16, 2012


    This site may contain affiliate links for which VFRworld may be compensated
    #8
  9. Lgn001

    Lgn001 Member

    Country:
    United States
    Joined:
    Nov 11, 2007
    Messages:
    1,855
    Likes Received:
    1
    Trophy Points:
    53
    Location:
    Russian River by Ocean, CA
    Map
    Based on the way they are located with reference to the cam/valves, I'd suspect that turning them clockwise would decrease clearance, and CCW would increase clearance.

    Great pictures, by the way.
     
    Lgn001, Jan 16, 2012


    This site may contain affiliate links for which VFRworld may be compensated
    #9
  10. MiddleTBabb

    MiddleTBabb New Member

    Country:
    United States
    Joined:
    Nov 10, 2007
    Messages:
    775
    Likes Received:
    1
    Trophy Points:
    33
    Location:
    Murfreesboro, TN
    Map
    Okay thanks a million for all the help. With a little more time I was able to get the rear cylinders finished and started on the front. :tongue:

    QUESTION:

    recently I saw a thread about a loud ticking noise not caused by the valves but caused by a spring that kept the gears from getting slack...

    what do i need to do to inspect that spring before I put this puppy all back together?:confused:
     
    MiddleTBabb, Jan 16, 2012


    This site may contain affiliate links for which VFRworld may be compensated
    #10
Related Topics

Share This Page