IJSBA · ski
IJSBA2024, SKL. A closed-list class. The craft must stay stock except where the rules allow otherwise, so anything unlisted is not permitted.
Places where the rulebook contradicts itself, or where a figure could not be settled. Nothing in this list is decided, and it sits here rather than in a footnote because it is what you would want before spending money.
29 permitted outright, 7 answered by our reading of the class rather than by a quoted rule, 0 the rules do not settle. Grouped by the answer, because an open class gives one answer to most questions and printing it once per part would say the same sentence forty times.
Not permitted, not listed in the rulesOur reading, not a rule we can quote at you. This class requires the craft to stay stock except where the rules allow otherwise, and this part is not on the list.
Not legal6 parts
Explicitly prohibited by this class document.
Not legal2 parts
SKL.3.6
Not legal1 part
Exhaust must remain stock as supplied by the manufacturer. Only a stinger insert and cooling lines are allowed. SKL.3.6
Not legal1 part
Only replaceable jets, needle valve and needle valve spring changes, choke removal and an aftermarket primer. SKL.4.1
Not legal1 part
Any modification to the reed cage assembly is prohibited. SKL.4.3
Not legal1 part
Hull extensions and trim tabs may NOT be used in Ski Lites, though mounting brackets may remain. SKL.2.7
OEM part required1 part
OEM tank, pickup, filler, filter, tap assembly and relief valve, unmodified. SKL.4.2
Not permitted, not listed in the rules5 parts
Not listed in this class document. Illegal under the closed-list principle.
Not permitted, not listed in the rules1 part
No aftermarket head allowance in SKL.
Not permitted, not listed in the rules1 part
Not listed in this class document, so illegal under the closed-list rule (SKL.1.1); SKL.8.2 also bars internal modification of the reduction nozzle.
Legal, within limits3 parts
Permitted subject to the universal limits in ijsba-globals.yaml constants.
Legal, within limits1 part
Modified or aftermarket ECU retaining original inputs, outputs and connections. Timing may be altered by slotting the trigger mounting plate or via an adapter plate. SKL.5
Legal, within limits1 part
Must fit the OEM battery box and be securely fastened. GP/Open/Freestyle/Sport GP additionally allow an additional battery, a new box and relocation.
Legal, within limits1 part
Aftermarket cylinder SLEEVE only, retaining the same port sizes and specifications as OEM, and permitted only where displacement is more than 10% below the 850cc maximum. Cylinder interchange between homologated craft of the same manufacturer is allowed subject to IJSBA restrictions. SKL.3.12
Legal, within limits1 part
Must also retain original PORT TIMING. +/-25.00% weight.
Legal, within limits1 part
Rebuild with replacement counterweights, crank pins, bearings and rods; total assembly weight within +/-5.00% of OEM; NON-FERROUS crank components prohibited; stroke and rod length may NOT change.
Legal, within limits1 part
Ferrous only. Rod length may not change.
Legal, within limits1 part
Extension may not be wider than the OEM plate, sides must be connected and radiused, and no fins, rudders or skegs. Max extension beyond the OEM plate: 100.00mm (3.94 in) Ski and Sport, 177.80mm (7.00 in) Runabout.
Legal, within limits1 part
Full-length type with at least one bar parallel to the drive shaft, all leading edges radiused, extending no more than 12.00mm (0.47 in) below the flat plane of the pump intake area.
Legal, within limits1 part
Max TWO. Max 38.00mm drop.
Legal, within limits1 part
The handlebar must be padded at the mounting bracket, or the crossbar padded if fitted. This is a tech-inspection item.
Legal, within limits1 part
Padding and/or mat kits may be added in every class. Where footwells exist they must be BLOCKED OFF during competition with no indentation into the footwell sides.
Legal, within limits1 part
Replacement bumpers allowed provided no hazard is created. A soft flexible water-spray deflector may attach to the hull sides or bond flange, not extending beyond the perimeter of the OE bumper or side moldings as measured by plumb line. A permanently affixed IJSBA-approved nose bumper is REQUIRED under GEN.8.12.
Legal, within limits1 part
Allowed in essentially every class. Universal prohibitions: no manually controlled devices that alter cooling water flow during operation, no electronically controlled valves or water injection unless original equipment, and in most stock classes no NEW fittings added to the cylinder head, cylinder or crankcase.
Legal, within limits1 part
Fixed-type or automatic valves only. Thermostats, pressure regulators and solenoids qualify. Manual actuation of any kind during operation is prohibited everywhere.
Legal, within limits1 part
Constant mass only, within the normally exposed areas of the hull, creating no hazard and requiring no modification or relocation of other parts. Water and any other fluid ballast is prohibited in every class.
Legal1 part
An insert in the stinger portion to reduce inside diameter, plus cooling lines added to the insert or stinger. SKL.3.6
Legal1 part
Changes to replaceable-type jets, needle valve and needle valve spring. SKL.4.1
Legal1 part
Modified or aftermarket reed valve PETALS allowed. SKL.4.3
Legal1 part
Must meet USCG, SAE J-1928 Marine or UL-1111 Marine backfire flame arrester standards.
Legal1 part
Modified or aftermarket filler cap allowed provided no hazard is created. The FILLER and RELIEF VALVE themselves must stay OEM.
Legal1 part
Aftermarket spark plugs of a different heat range are allowed in every class that addresses them.
Legal1 part
Explicitly permitted by this class document.
Legal1 part
Aftermarket steering shaft, steering shaft holder, handlebar holder and steering cables are allowed. Quick-turn modifications that alter the steering ratio are allowed in most stock classes.
Legal1 part
The original bilge pump may be modified or disconnected and aftermarket bilge draining systems are allowed, provided no hazard is created.
Legal1 part
Replacement engine mounts are allowed in every class that addresses them. Ski GP, Vintage and Freestyle additionally allow a modified or aftermarket ENGINE BED with the engine repositioned in the hull.
Legal1 part
Replacement starter motor and bendix are allowed in every class that addresses them.
IJSBA 2024, SKL, read from the rulebook on 2026-09-07, not verified by a racer. Read the rule yourself, Ski Lites. Every IJSBA class · where the rulebooks differ.
This is one class. Every part below also has a page of its own showing where it stands across every class this body runs, and legality by part is the index of them.
49 parts read · 29 permitted outright · 2024 rulebook