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Thread: 720 rotary face

  1. #1

    720 rotary face

    Hi all, i just bolted matched 720 case halves together with a new crank installed and noticed the rotary face at the rear port is out slightly creating a "lip". The rotary faces are in great shape.

    Now I'm debating loosening the bottom case halve to see if I can shift it over a bit. It's probably only a millimeter off but just enough to create a lip for the the rotary valve to catch on.

    Anyone had this happen before? Solutions / suggestions - I'm all ears....


  2. #2
    wkuadam07's Avatar
    Join Date
    Feb 2013
    Bowling Green, KY
    Did you loose your dowel pins? That shouldn't ever be a problem with the dowel pins installed correctly... My guess is that you need to split it again and start all over...

  3. #3
    99.9% sure there are no dowel pins on the 720's. It's not in the manual either. The manual actually says to install the armature plate temporarily to align the cases - which I didn't do. The last 720 that I did came out perfectly aligned - did this one the same way. Just wondering if I can loosen it up and bump the bottom to align it.

  4. #4
    wkuadam07's Avatar
    Join Date
    Feb 2013
    Bowling Green, KY
    Depends what you sealed it with... I use ThreeBond 1211... there isn't any moving that stuff around after it sets up. The last 720 I pulled apart had dowel pins... but it was a 2003 GTI LE engine.

  5. #5
    put it together with Yamabond - I think she'll move a titty without breaking the seal...but I'm being really optimistic because if I have to tear this down again....

  6. #6
    Turns out they were aligned. I just had a slight burr or rough edge about 3/4" long toward the one side which made me think it was not matched good (ski was disassembled, parts thrown in bottom of ski and left for dead by a hack mechanic shop b4 we got it).
    I used some very fine steel wool to cure it - cleaned up nice and got her running this past weekend.

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