yz400f

Discussion in 'Thumpers' started by shawy39, Sep 26, 2013.

  1. shawy39

    shawy39 n00b

    Joined:
    Sep 26, 2013
    Oddometer:
    1
    Hi I have recently bought a 99 yz400f with only a little compression,
    I have read a few forums which intercate that it is a common fault for the valves to stick open so I wipped it all of pisten is fine done a pressure test and yep 2 valves were slightly open so got them re seated and cleaned up what I need to no now is what are the torque setting for the head? any help would be great.

    chris
    #1
  2. DakotaRon

    DakotaRon Adventurer

    Joined:
    Jan 2, 2012
    Oddometer:
    15
    Location:
    Minot, ND
    Be sure and apply moly lube to the bolt threads and washers before you torque the head. Then torque to 34 ft/lbs using a criss cross pattern sequence. I am glad you found it an easy fix. Happy Roosting!
    #2
  3. PineyMountainRacing

    PineyMountainRacing Oops....

    Joined:
    Jul 2, 2008
    Oddometer:
    5,250
    Location:
    Sarasota, FL / Sylva, NC
    I've got the 99 WR400F, what a hoot. All it's lacking is a tag!
    #3
  4. dougfromindy

    dougfromindy I smell premix

    Joined:
    Aug 15, 2008
    Oddometer:
    3,835
    Location:
    Indpls, IN Lexington, MI
    great trail bike with big power
    my spark plug blew out, no more threads, just fixed it
    i got lighting, baja designs 180w ext stator set up
    [​IMG]
    #4