Announcement

Collapse
No announcement yet.

Stuck pistons, yet in-gear rotating rear-wheel?

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

    Stuck pistons, yet in-gear rotating rear-wheel?

    Hi!

    When I bought my GS 3 months ago, PO said engine is seized from bike having stood for 8 years. I didn't test if wheel was locked when in gear.
    I poured kerosene into sparkplug holes, to free pistons. After a week or so, I turned backwheel when it was in gear & it was able: most resistance being in 1st gear and least in 5th gear. In neutral, wheel moves freely, without any resistance. I thought: problem solved.

    The starter motor didn't want to turn engine.
    I pulled the sparkplugs again and realized the pistons are not moving up and down (long screwdriver in sparkplug holes aren't being pushed upwards, or lowering with pistons, when bike is pushed and in gear). The position of the pistons stays the same (I verified with a flashlight as well).

    Signal generator cover bolts were loosely torqued by PO. I opened the cover and turned 19mm nut CW and it was able: even though pistons are stuck. But after a few turns the nut starts tightening.

    Did the PO maybe loosen the 19mm nut via turning it CCW, that being the reason that the nut can turn CW a few times before tightening?
    Solution then just being to torque 19mm nut?

    Any ideas or solutions on getting rear-wheel to lock?
    My thinking being this: once rear-wheel locks, I'll definitely / easily be able to free (soaking) pistons.
    That is the state it should be in with frozen pistons, after all.
    Might something have been disconnected that causes this phenomenon?
    Maybe connected to the clutch plates being frozen?

    Thank you!

    #2
    My thinking tells me to pull the clutch cover. Seems to me that if the wheel turns with the bike in gear theres a [problem in the basket...which may also be jamming the crank and thus making the engine seem seized.
    MY BIKES..1977 GS 750 B, 1978 GS 1000 C (X2)
    1978 GS 1000 E, 1979 GS 1000 S, 1973 Yamaha TX 750, 1977 Kawasaki KZ 650B1, 1975 Honda GL1000 Goldwing, 1983 CB 650SC Nighthawk, 1972 Honda CB 350K4, 74 Honda CB550

    NEVER SNEAK UP ON A SLEEPING DOG..NOT EVEN YOUR OWN.


    I would rather trust my bike to a "QUACK" that KNOWS how to fix it rather than a book worm that THINKS HE KNOWS how to fix it.

    Comment


      #3
      Hi Chuck Hahn

      Thank you for your reply.

      19mm crankshaft nut was able to turn freely (with a seized engine!), because of the 'fingers' on the timing advance mechanism being broken off.

      Don't you think there could be other reasons for the gearbox not turning the crank?
      Like camchain being off its track, etc.

      What possibilities can you think of?

      Your thoughts would truly be appreciated.

      Comment


        #4
        Like Chuck said... Pull the clutch cover and see what's going on there. No mater what the problem is under the ignition cover or with the timing chain, only the trany and clutch could cause the rear wheel to spin when in gear on a locked motor. The fact that it turn harder in 1st then in 5th indicates that the trany is switching gears.

        Post some pictures of what you have and areas of concern. Maybe some well educated eyes can give you a better idea of what's happening.
        Last edited by JTGS850GL; 06-03-2014, 03:00 PM.
        http://img633.imageshack.us/img633/811/douMvs.jpg
        1980 GS1000GT (Daily rider with a 1983 1100G engine)
        1998 Honda ST1100 (Daily long distance rider)
        1982 GS850GLZ (Daily rider when the weather is crap)

        Darn, with so many daily riders it's hard to decide which one to jump on next.;)

        JTGS850GL aka Julius

        GS Resource Greetings

        Comment


          #5
          If your engine is seized you may as well just tear it down and rebuild it. Even if you do get the pistons freed up you still will have terrible compression. If the engine really is locked and you can turn the back wheel in gear the problem is in the clutch.

          Comment

          Working...
          X