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Motor won't turn after rebuild

Discussion in 'The Garage' started by Andy L, Apr 28, 2022.

  1. Andy L

    Andy L XS400 Member

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    Hi everyone,

    I had split the crankcase on a working motor to make a repair. I did so successfully following instructions in a thread on here (thanks for that!). After taking the block off and cleaning it up, i put it all back together, up to the camshaft part.

    At that point I tried turning the motor via the alternator bolt, and it'll only turn about maybe an eighth of a revolution (in either direction) before sounding like something is hitting something internally, at which point it will not budge.

    I didn't remove the pistons, connecting rods, or touch the crankshaft, so not really sure what could be going on.

    I'm going to double-check the starter chain, the cam chain isn't binding, and it is indeed in neutral. I also pulled out the kickstart to ensure it wasn't interferring.

    I'm just wondering if anyone has any suggestions on where to look. I really don't want to have to split this thing again, but will do so if necessary.

    Thanks in advance!
     
  2. So the cylinder and the head came off, and now you have them back on and remounted. Are the cams installed or not?
     
  3. Andy L

    Andy L XS400 Member

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    Not fully, no. It was installing the cog that i tried turning the motor to no avail.

    There doesn't appear to be anything on the cam portion that would be impeding things.

    Thank you!
     
  4. Andy L

    Andy L XS400 Member

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    The cam gear...sorry, just using the manual language!
     
  5. CaptChrome

    CaptChrome XS400 Addict

    Check that you are holding up the timing chain so that it will rotate without jamming and try to turn it over again. The chain should rotate over your finger as the engine rotates.
     
  6. Andy L

    Andy L XS400 Member

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    Tried this, same result. The motor just stops with a solid "clunk".
     
  7. Well, that's a head scratcher, does the "clunk" come from the crankcase portion or nearer the back where the transmission is?
     
  8. Andy L

    Andy L XS400 Member

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    It seems more on the front side, around the cylinder block area. It's a pretty pronounced sound.

    Guess I'll be pulling it apart once again!

    Thanks!
     
  9. Maybe you'll find my 10 Millimeter socket....
    LOL
     
    CaptChrome likes this.
  10. Andy L

    Andy L XS400 Member

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    I hope it's as easy a fix as that!
     
  11. Buddha

    Buddha XS400 Addict Top Contributor

    Hey Andy
    A shot in the dark here. Is the engine out of the bike? If so can you turn it upside down and try turning it over? Maybe something may fall out onto the bench:umm:
    Seriously though, I would be pulling it apart and recheck all my work.
     
  12. Andy L

    Andy L XS400 Member

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    It is indeed still out, and I'll be sure to flip it every which way once it's apart. Thanks!
     
  13. Andy L

    Andy L XS400 Member

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    For those who're interested, I pulled the motor apart again and found the issue:
    I put the longer oil pump bolt in the wrong hole, which was just poking through the crankcase and catching a part of the crankshaft.

    The oil pump was the one part of the disassembly/reassembly I didn't consult the manual on, as it seemed so straightforward. Thankfully it was a simple fix.
     
  14. Buddha

    Buddha XS400 Addict Top Contributor

    :cheers: Don't you just love stories with happy endings?
     
  15. Sweet! Thanks for the update! I'll bet you never do that again.
    A lesson learned the hard way, is one seldom forgotten.
     
  16. Andy L

    Andy L XS400 Member

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    They are usually the best kind!
     
  17. Andy L

    Andy L XS400 Member

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    Quite right! Thanks again for chiming in on the issue!
     

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