Yamaha XT600 Front Sprocket Removal

Discussion in 'Motorbike Technical Discussion' started by mazdaman851, Jan 30, 2005.

  1. mazdaman851

    mazdaman851 Guest

    The bike is a 1991 XT600EB dual sport. I can't find a manual­ for it
    anywhere seeing as Clymer left off at 1989. I have the new
    s­prockets for it but need to know which way the front sprocket comes
    o­ff. Is it standard or reverse (left or right) threads? Also, does
    anyo­ne know how much torque it's put on with? And what's the best
    method for­ holding the motor from cranking while I'm trying to turn
    the nut? TI­A
    If anyone knows where I can get a manual for the bike that w­ould be a
    great help too!
    mazdaman851, Jan 30, 2005
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  2. front sprocket comes o­ff. Is it standard or reverse (left or right)

    I have never seen a reverse threaded sprocket nut on a motorcycle. One
    would also expect the nut that holds the alternator rotor onto the end
    of the crankshaft to be reverse threaded, but it's not...
    Probably about 50 ft-pounds...
    I'm trying to turn the nut?

    You might have somebody step on the rear brake pedal while you break
    the nut loose and tighten it. If that doesn't work, park the motorcycle
    with the front wheel against an immovable object, put the transmission
    into 5th gear and loosen the nut. Park the rear wheel against something
    when you tighten the nut...

    When I change countershaft sprockets on bikes that have cast aluminum
    wheels, I stick a piece of wood through the spokes so the hweel can't
    turn when the wood hits the swing arm...

    But you will probably bend some wire spokes if you try that with your
    krusty kritter, Jan 30, 2005
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  3. mazdaman851

    mazdaman851 Guest

    Ok. I will give your suggestions a try. I ask because late in the
    summer I tried getting the countershaft sprocket off - I had it in 1st
    gear, wood thru the spokes, one hand on the rear brake while trying to
    break it free with the other hand. If I recall correctly I had a
    cheater bar on the end of the ratchet as well. I may have been a little
    timid with it though too so as not to break or snap anything or bend
    any spokes as you say. What's the reason for putting it into 5th gear
    while turning the nut? Thanks again.
    mazdaman851, Jan 30, 2005
  4. mazdaman851

    Paul Cassel Guest

    Is there a locker on the nut? Don't do the wood thru the spokes as
    that's hard on the wheel. Use KK's foot on brake only (get a helper to
    really mash down if necessary). If it's frozen, then use AeroKroil.
    Paul Cassel, Jan 30, 2005
  5. mazdaman851

    mazdaman851 Guest

    No, no locker on the nut other than a cotter pin. I've never heard of
    AeroKroil. Where is it available?
    Btw, would Godzilla's foot be ok? I misplaced KK's number! :) Thanks!
    mazdaman851, Jan 30, 2005
  6. Theoretically, it keeps the wrench from using a lower gear's greater
    torque multiplication to easily turn the engine over against
    krusty kritter, Jan 31, 2005
  7. mazdaman851

    Paul Cassel Guest

    Industrial supply places near me carry it. You can do a a Web search or
    make your own local calls. It is a penetrating oil that makes WD40 look
    like sludge. I spray it on exhaust systems which are years old and they
    just come apart w/o tools after about a .5 hr soak.

    This s/b NOT that big a deal.
    Paul Cassel, Jan 31, 2005
  8. mazdaman851

    OH- Guest


    Strange. What sort of strange beast is a XT600EB? What
    market is it sold on?
    The reason I'm asking is that all XT600 I've seen (in Sweden)
    have had a folding washer to lock the countershaft sprocket.
    Often this will not work and a drop of Loktite is called for
    and that does not make it easier to loosen it ;-)

    A cotter pin sounds a bit rattely for this application.
    OH-, Jan 31, 2005
  9. If this is the transmission output sprocket, you'd want the
    bike in low gear to help keep the engine from cranking.
    Rob Kleinschmidt, Jan 31, 2005
  10. Try bumpstarting a bike in low gear and top gear. See which one
    turns the engine more easily. You want low gear to keep the wrench
    from turning the engine over. This is assuming you're working
    on the output end of the transmission.
    Rob Kleinschmidt, Jan 31, 2005
  11. Back in the old days of run-and-bump starts at the beginning of
    roadraces, the riders would put their big singles into *second* gear,
    as they couldn't push against first gear with their dragging clutches
    and the heavy weight oil in the separate tranny...
    krusty kritter, Feb 1, 2005
  12. Point being that top gear is the one which turns the engine over
    most easily while low gear turns it over least easily. If you
    want to use the engine to help restrain transmission output,
    the bike should be in low gear.
    Rob Kleinschmidt, Feb 1, 2005
  13. You will get the most crankshaft motion if you put the tranny into low
    gear. When you're breaking the nut loose, it doesn't matter much if the
    crankshaft turns and tightens up the cam chain. An automatic tensioner
    might even take up the slack in the back of the chain...

    But re-tightening the nut while the tranny is in gear turns the engine
    backwards and that might jam the cam chain against the sprockets...

    You might even jump a cam sprocket tooth if your cam chain tensioner
    hasn't been taking up the slack...
    krusty kritter, Feb 1, 2005
  14. was attempting to loosed the front sprocket nut... it snapped like a

    You may need something stronger than an old broomstick. You may need a
    2x4, if you can slide one between the spokes and the swing arm...

    Front sprocket on a Bandit is probably torqued to 80~100 ft.lbs., so
    with about a 3:1 final drive reduction, the force against the wood is
    about 240~300 pounds...

    I used an old steel car tire iron once, to stop the rear wheel from
    turning on a GS-1100. Before I heard my torque wrench click, the tire
    iron bent...

    But the OP wanted to break the nut loose on a Yamaha dualsport bike.
    The torque on the nut on that bike is probably only about 50 ft.lbs.,
    so an old broomstick might just be strong enough...
    krusty kritter, Feb 3, 2005
  15. mazdaman851

    Rob Munach Guest

    How about some air tools!
    Rob Munach, Feb 3, 2005
  16. mazdaman851

    OH- Guest

    I don't have the exact figure but I assure you that it's a bit more than
    that, I've done it a few times. I used my torque wrench when loosening
    the nut just because it has a long handle and would give me some
    Standing on the rear brake lever, I'd reach over the bike to use the
    wrench. Sometimes it's an advantage to be a bit tall.
    OH-, Feb 3, 2005
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