John Deere Engine Miss

Discussion in 'Mechanic and Repair' started by MBDiagMan, Nov 13, 2013.

  1. Restrorob

    Restrorob LawnSite Fanatic
    Posts: 11,024


    I don't know that there's more than one shim in each bucket, You may have to measure the one that's in it now and figure what thickness will be needed to get you to the proper spec......


    #27 is the shim and I added the different sizes, You'll likely end up at your local Deere dealer if you need any;


    [​IMG]
     
  2. MBDiagMan

    MBDiagMan LawnSite Senior Member
    Posts: 852

    Thanks VERY much Restro. If I had not seen this I might not have figured out where the shim is. I sort of expected a shim under a rocker stand or something. I hope I don t have to remove the cams to access them.

    My wife and I are going to town for our weekly shopping and errands. I am hoping it will be a little warmer when I get back so I can pull the cam cover.

    This is extremely helpful and I appreciate very much you taking time to find and post it.
     
  3. Restrorob

    Restrorob LawnSite Fanatic
    Posts: 11,024

    Well, It's been over 30 years since I worked at a motorcycle shop doing this style valve adjustments...... I just can't rattle the brain enough to remember if the cams had to come out, But I want to think they do since looking at the breakdown......
     
  4. MBDiagMan

    MBDiagMan LawnSite Senior Member
    Posts: 852

    Thanks for further response Restro.

    I too believe the cams will have to come out. We had stiff North Winds that made it uncomfortable in my tin barn converted to shop type building. We have an ice storm today. I will be off Wednesday through the following Sunday, so I hope to get a chance at it then.

    If the cams do have to come out, I will have to find a manual somewhere to make sure I keep everything in time.

    If the cams do have to come out, it sure does cast this engine in a bad light as far as I'm concerned. It will be a pain in the neck to deal with.

    BTW, is that item 27 the cam follower friction surface?
     
  5. Restrorob

    Restrorob LawnSite Fanatic
    Posts: 11,024

  6. MBDiagMan

    MBDiagMan LawnSite Senior Member
    Posts: 852

    Thanks Restro! You da' man!
     
  7. MBDiagMan

    MBDiagMan LawnSite Senior Member
    Posts: 852

    I got the manual and have pulled the cover. The shim is changed by rotating the engine such that the cam opens the valve after having rotated the sleeve below the shim to expose a notch. A special tool is put into the notch that keeps the valve open while rotating the cam so the heel is down. You then use a pick to work the shim out.

    A couple of valves are slightly tight, by only a thousandth, but I will get them to spec. I ordered the tool and it will be a week before I get it. The shim is indeed the cam follower surface.
     
  8. MBDiagMan

    MBDiagMan LawnSite Senior Member
    Posts: 852

    Restro,

    After getting a chance to read the manual further, I discovered that the valve lash spec's are:

    Intake .007" +/- .002"
    Exhaus .010" +/- .002"

    The exhaust valves are right at .010" while the Intakes are a tight .006", which is still within spec.

    Regardless of valves being adjusted within spec, the fact remains that the hot compression on that cylinder is going down from 190 to 150.

    Do you think I'm wasting my time, putting those intake valves to .007"?

    Thanks VERY MUCH for sharing your time and expertise.
     
  9. Restrorob

    Restrorob LawnSite Fanatic
    Posts: 11,024

    Well..... The idea was to check the valves, You've done that and they are with-in the book spec. so no I wouldn't bother them. A cylinder leak-down test may show a ring issue.....
     
  10. MBDiagMan

    MBDiagMan LawnSite Senior Member
    Posts: 852

    Thanks for keeping me between the curbs on this Restro. You're right, there's no reason to screw with the valves. I will do a leak down and listen for where I hear the escaping air.

    Do you think that there is any chance it could be the headgasket?

    Gotta love a Chinese engine.
     

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