Learned some valuable info today....

Discussion in 'Motorized Bicycle General Discussion' started by fall_down_stand_up, Oct 30, 2009.

  1. fall_down_stand_up

    fall_down_stand_up New Member

    Joined:
    Apr 26, 2009
    Messages:
    555
    Likes Received:
    0
    When I first buy a new engine I tork the head bolts down to 12fp....Well I bought a couple of new Raw engines and in the owners manual it talked about maitance and it said to check your head bolts on a regular basis,so I checked my bolts on my bike im riding now(not the Raw engines) and my head bolts were only torked down to around 8fp,They had really loosened up in the 150miles I have put on this engine.....
    So to keep from getting blown gaskets check the tork on your head bolts regularly....
    John-John
     
  2. 2door

    2door Moderator
    Staff Member

    Joined:
    Sep 15, 2008
    Messages:
    16,308
    Likes Received:
    30
    John,
    You did the right thing by using your torque wrench to 'check' the tightness and you found it out of spec.
    Here is where a lot of guys get into trouble because they mix up, 'Tighten and 'Check''
    When an engine is brand new, never run, the head bolts/nuts should be torqued to the recommended value; somewhere in the range of 12 foot pounds. Then they should be 'checked' again after the engine has reached operating temperature the first time. After that they can be 'checked' periodically but not necessarily 'tightened'. Too many guys have made the mistake of thinking they need to see some rotation of the bolt/nut when they 'check' the tightness and that's where they end up twisting off studs or damaging threads. By 'checking' one only needs to apply recommended torque to the bolt/nut. If it doesn't move when applying the 12 ft. pounds then it's tight. It does not need to be tightened more just because they're being 'checked'. Thanks for the post. I hope others read it and like you, learned something today.
    Tom
     
  3. fall_down_stand_up

    fall_down_stand_up New Member

    Joined:
    Apr 26, 2009
    Messages:
    555
    Likes Received:
    0
    Thanks 2door....I have learned over time that if I double check every bolt on the bike for tightness before I ever first start it I get alot longer life out of the engine....If One bolt is loose it can cause all kinds of damage....
     

Share This Page