SORC ballot #3 announcement of rules adoption
  • SORC
    ballot #3 announcement of rules adoption

    The enhanced
    drilling of Yamato engines for cooling has passed by the majority of the

    The new rule
    below will be added to our technical manual with pictures.  There is also a “how to

    called the “drilling guide” that is being created and will be available soon in
    a PowerPoint




    Remove Rule #16, Page 73 of our tech manual and replace with a new rule below:

    1) The water
    inlet hole(s) may be repaired with weld or plastic compounds.

    2)  It is permissible to create a groove from the
    forward side entrance of the original hole location thru the leading edge of
    the exhaust snout. 

    3) The lowest
    point of the water inlet hole(s) and groove may not be more than 1.400” below
    the bottom of the cavitation plate.

    4) The
    original contour of the exhaust snout must be maintained.

    5) This is
    permissible on all approved Yamato engines in classes 25ssr, CSR, CSH and

    6) See photos
    on Page 75 of this manual.



    1) Sufficient
    testing has occurred after drilling out the leading edge of the water intake
    area. It has been found that the motor will now cool sufficiently.

    2) With this
    rule change it will be much easier for our inspectors. They will not have to
    measure the intake hole, slot or groove size. Only depth location.

    3) We will
    not have our drivers disqualified for the hole that they drilled out themselves
    and therefore made it too large or too small by thousandths of an inch.

    4) Actually,
    no one has to do this. Each driver can adjust this hole size if needed
    depending on the specific engine, set up and propeller.

    5) In
    addition to the photos being added on page 75, there will be a "drilling
    guide" added to the Stock Outboard Resource page on the APBA website.  This will show our members how to accomplish

    If approved
    by the SORC, this rule would go into effect 30 days after posting on the APBA


    Please see
    your local commissioner if you have any questions or email me at

    Thank you,

    Jeff Brewster

    Outboard Chairman

    SORC ballot #3 announcement.docx

    APBA Member #: 1859
    Boat #: 59-S
    Classes: 300SSH, BSH, 25SSH & Csr Marathon
    Region 6