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CG125 woes!

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  • CG125 woes!

    Morning Gents,

    I made the terrible mistake of telling my brother that the CG125 engine is bullet proof.

    He then proceeded to test this theory by running it without oil.

    So I am now the proud owner of a CG125 that's in need of some work, I've replaced quite a few bits so far:

    New valves,
    New springs,
    New pushrods,
    New barrel,
    new piston,
    Cam Followers and pinion.

    The poor thing is still clicking away big time when running, so loud you can't talk next to it. A test turn of the flywheel (as if doing clearances) produces a rather loud click from both valves when they're near full extension.

    I've currently stripped out the valves and springs again to see if there's anything I've missed, I've moved the valves freely in their guides without the springs and they move smooth as silk.

    I should add it's a brazil model with the oil seal only on the exhaust valve.

    So, TLDR, CG valves clicking on return, WTF?

    I'd appreciate some advice or potential pointers.

  • #2
    If it's been run out of oil I think the crank may have suffered and I'd think about taking a look at it however, turning the crank by had and the valve clicking is a different problem. Are there any contact marks on the piston crown from the valves ? Are you sure you've got it right putting it back together ? I'd reread the manual and double check everything.
    They are bomb proof but not idiot proof.


    • #3
      Hahaha very true!!

      I've rebuilt the toptend multiple times. To check, IveI even tried a seperate head that had the exact same problem with the valves.

      The only thing I haven't checked is the cam, which, if its damaged, the followers may be causing the clicking up top, dropping off too quickly or something.