Freestyle machines must conform to the modified class rules. It is bullchit but they (ijsba) has to draw a line somewhere. Hulls must meet the rules or they are not legal.
The Japs are chickenchits for their protest. They got their azzes handed to them. My bet is next year even they will be on a short nosed shortened SJ based aftermarket hull.
9.1 MODIFIED CLASS COMPETITION
Competitors in this class are allowed modifications to gain maximum machine and engine performance. Watercraft
competing in this class must conform to the specifications which follow.
FREESTYLE ADDENDUM: Amateur and Pro Freestyle classes are allowed identical modifications with the
exception that Amateur Freestyle Competitors may compete on PWC with a maximum displacement of 900cc
while Pro Freestyle Competitors may compete on PWC with a maximum displacement of 1200cc.
9.1.1
All watercraft must remain strictly stock, except where rules allow or require substitutions or modifications.
Changes or modifications not listed here are not permitted. Some original equipment components may not comply
with IJSBA rules.
NOTE: When rules permit or require equipment to be installed, replaced, altered or fabricated, it is the sole
responsibility of the rider to select components, materials and/or fabricate the same so that the watercraft
operates safely in competition.
9.1.2 Original equipment parts may be updated or backdated to original equipment parts of the same model. The part must be a
bolt-on requiring no modifications to that part or any other parts except where rules allow substitutions or modifications.
(Refer to Model Homologation
listing on page 10-11.)
9.1.3 Sound level shall not exceed 86 dB(a) at 22.86m (75 ft.).
See Section 19.5 (pg. 73).
9.1.4 Engine fuel must consist of gasoline meeting the criteria defined in
Section 19.4.3 (pg. 73).
9.2 HULL
9.2.1 All watercraft must have a flexible tow loop attached to the bow. The tow loop should be made of a flexible material (e.g.,
nylon strap, rope, etc.) so as not to create a hazard. Tow hooks, which protrude beyond the plane of the hull, must be
removed.
9.2.2
Deck: Original equipment deck must be used. Deck repairs may be made, provided they do not alter the standard
configuration by more than 2.00mm (0.08 in.). The deck’s bond flange may not be modified. Deck may be internally
reinforced. Fasteners may be installed through the hull and deck for the purpose of securing components to interior
surfaces, provided a hazard is not created.
If upper and lower components of the original equipment bond flange are separated and rejoined, they must be rejoined
by the same method as original equipment (i.e., bonded together with a high-strength adhesive). (See bond flange
diagram in Appendix.)
Freestyle ONLY:
Footholds may be installed into the footwells. If the same watercraft is used for racing, the footwells
must be blocked off, allowing no indentation into the footwell sides.
Freestyle ONLY: The
top deck of freestyle craft may be modified or aftermarket, providing the following: The top deck
must resemble the original top deck of the homologated watercraft; length and width of top deck must be within 13mm
(0.50 in) of the original component; the craft must function as originally intended. Fuel fillers may be relocated internally.
The deck and hull must be joined by the same method as the original hull and deck (i.e., bonded together with a highstrength
adhesive). If upper and lower components of the original equipment bond flange are separated and rejoined, they
must be rejoined by the same method as original equipment (See bond flange diagram in Appendix.)
The decision of the Technical Director and/or Race Director regarding modifications will be final. Any question regarding
the legality of modifications should be directed to the IJSBA or IJSBA affiliate prior to use in competition.
9.2.3 Hull: Hull may be modified or aftermarket but cannot exceed the length or width of the original equipment upper deck
component of the bond flange as measured by a plumb bob (bumpers removed). Fins, rudders, skegs and other
appendages that may create a hazard will not be allowed.
The decision of the Technical Director and/or Race Director regarding modifications will be final. Any question regarding
the legality of modifications should be directed to the IJSBA or IJSBA affiliate prior to use in competition.
9.2.4 All watercraft may be equipped with a maximum of two sponsons. Original equipment sponsons may be modified,
aftermarket, repositioned or removed. Overall length of each sponson shall not exceed 91.45cm (36.00 in.). Sponsons
shall not protrude from the side of the hull by more than 100.00mm (3.94 in.) when measured in a level horizontal plane.
The vertical channel created by the underside of the sponson shall not exceed 63.00mm (2.50 in.). No part of the sponson
shall extend downward below the point at which the side of the hull intersects the bottom surface of the hull by more than
63.5mm (2.50 in.). Aftermarket or modified sponsons must exceed 6mm (0.24 in.) in thickness. All leading edges must be
radiused so as not to create a hazard. Sponsons may not be attached to the planing surfaces of the hull. Fins, rudders,
skegs and other appendages that may create a hazard will not be allowed. (See diagrams in Appendix.)
Ski Division Only:
Sponsons may be attached to the inside of the bond flange, but no part of the sponson may extend
more than 38.00mm (1.50 in.) below the lower part of the bond flange (bumper removed). Sponsons attached to the inside
of the bond flange shall not protrude outside the bond flange (bumper removed) when measured in a level horizontal
plane.
The decision of the Technical Director and/or Race Director regarding modifications will be final. Any question regarding
the legality of modifications should be directed to the IJSBA or IJSBA affiliate prior to use in competition.
9.2.5 Intake grate may be modified or aftermarket. Intake grate is required and must be the full-length type with at least one bar
running parallel to the drive shaft. Grates may not extend more than 12.00mm (0.47 in.) below the flat plane of the pump
intake area. All leading edges must be radiused so as not to create a hazard.
9.2.6 Pump cover plate may be modified or aftermarket. An extension may be added to the rear of the pump cover plate but
shall not exceed the width of the original equipment plate. Modified and aftermarket plates must not extend more than
100.00mm (3.94 in.) beyond the end of the original equipment plate for Ski and Sport Division or 177.80mm (7.00 in.) for
Runabout Divisions.
The sides of the extension must be connected to the radiused portion of the pump plate so as not
to create a hazard. (See diagram in 9.2.6 Appendix.) Fins, rudders, skegs and other appendages that may create a
hazard will not be allowed.
9.2.7 Aftermarket trim tabs, either fixed, automatic and/or rider controlled, may be used. Original equipment trim plates that are
detachable from the hull may be removed or replaced when installing aftermarket trim tabs. Trim tabs cannot exceed the
width of the planing surface or extend rearward more than 100mm (3.94 in.) beyond the end of the original planing
surface. All hull extensions mounted on the hull’s transom will be considered as a trim tab. All edges must be radiused so
as not to create a hazard. Fins, skegs, rudders and other appendages that may create a hazard are not allowed.
9.2.8 Replacement bumpers may be used provided a hazard is not created.
9.2.9 A soft, flexible water-spray deflector may be attached to the hull sides or to the bond flange provided a hazard is not
created. No part of the deflector may extend beyond the perimeter of the original equipment bumper or side moldings as
measured by a plumb line.
9.2.10 Handlebar, throttle, throttle cable, and grips may be modified or aftermarket. Handlebar cover may be modified or
removed. Aftermarket switches and switch housings may be used. Steering shaft, steering shaft holder and handlebar
holder may be aftermarket. The handlebar must be padded at the mounting bracket or, if it has a crossbar, the crossbar
must be padded. Aftermarket steering cables are allowed.
9.2.11 Ski Division Only: Handlepole (and mounting bracket) may be modified or aftermarket provided it functions as originally
designed. Handlepole attaching point may be reinforced.
9.2.12 Sport and Runabout Division Only: Seat assembly may be modified or aftermarket. Seat height may be changed.
9.2.13 Padding and/or mat kits may be added and custom painting is allowed. The surface finish of any metal component outside
the hull area above the bond flange may be polished, shot peened or painted.
9.2.14 Original bilge pump may be modified or disconnected. Aftermarket bilge draining systems that do not create a hazard are
allowed.
9.2.15 Engine compartment foam may be removed, modified or aftermarket.
9.2.16 Storage covers, hatches, instrument cowlings and engine covers may be modified or aftermarket provided a hazard is not
created and the OEM appearance is maintained. Additional engine compartment ventilation is allowed. Original equipment
vents may be shielded or plugged. Handles, drop-in type storage buckets and bolt-on type mirrors may be modified,
aftermarket or removed provided a hazard is not created.
9.2.17 Ballast weight may be added within the normally exposed areas of the hull to alter the handling of the watercraft provided
a hazard is not created. Only weight consisting of constant mass (i.e., water or other fluid is not allowed) that does not
require the modification or relocation of any parts will be allowed unless such modification or relocation is specified by
other rules.
9.3
