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Class Legality

IJSBA · runabout

Runabout Limited

IJSBA 2022, RAL. A closed-list class. The craft must stay stock except where the rules allow otherwise, so anything unlisted is not permitted.

  • 4Not legal
  • 5OEM part required
  • 3Not permitted, not listed in the rules
  • 1The rules do not say
  • 2Governed by the parent class
  • 22Legal, with conditions
  • 23Legal

Read out of the published IJSBA rulebook on 2026-09-07, so confirm anything that decides a purchase. The full note is at the foot of the page.

Running the class

Eligible craft
Craft must remain strictly stock except as specified. Must comply with the online Model Homologation listing.
Displacement limit
Two-stroke: must not exceed the class designation. Four-stroke: no cc figure stated.
Licence or tier
Not stated.
Minimum weight
Not stated in this document.

Read from the same class section as the part answers. The rider side of the sport, tiers, ages, licences and what gets inspected, is set out across the bodies at Racing.

Open questions on this class (4)

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.

  • No four-stroke exhaust rule appears. Confirmed by a second targeted fetch - a real gap.
  • No weight rule, no rider age/licence, no racing number rule, no numeric boost limit, no eligible-model list.
  • Wear ring rules are not restated - legality depends on RAL.1.1 inheritance from Stock.
  • 2022 document, predates the 2025 Superstock and RNA documents.

What the rules say (60 parts)

23 permitted outright, 22 permitted with stated conditions, 4 refused by a rule we can quote, 5 held to the original part by a rule we can quote, 3 refused by our reading of the class rather than by a quoted rule, 1 the rules do not settle and 2 answered by the parent class. Grouped where the same rule gives the same answer, so two "Not legal" groups can sit side by side under different rules.

What each answer below means

Not legal
This comes off. The rules refuse it in this class.
OEM part required
This comes off. Only the part the manufacturer fitted is allowed here.
Not permitted, not listed in the rules
Treat it as coming off. The class requires the craft to stay stock except where the rules allow otherwise, and this part is not on the list, so this is our reading rather than a rule we can quote at you.
The rules do not say
Unanswered. The rules do not settle this, so ask the club before you rely on it.
Governed by the parent class
Answered by the parent class rather than here, and the parent is named in the answer.
Legal, with conditions
Keep it, but measure it: the rules permit this part only inside stated limits.
Legal
Keep it. The rules permit this part in this class.

Read the refusals as a list of work. Anything below marked Not legal, OEM part required, or Not permitted has to come off the machine, or go back to the standard part, before it races in this class.

OEM part required1 part

Modifying the OEM waterbox is prohibited. RAL.4.7

OEM part required1 part

RAL.5.1 keeps the turbocharger or supercharger impeller housing stock as furnished, so the unit itself stays OEM. Every internal part, the pulleys, tensioners and intercoolers may be modified or aftermarket, with a spacer for a larger impeller where nothing else must change, which makes it a modified OEM unit rather than an aftermarket one. RAL.5.1

OEM part required1 part

The hull may be repaired but not otherwise modified, and a repair may not alter the original configuration by more than 2.00mm (0.08 in.). RAL.2.2

Not permitted, not listed in the rules1 part

No aftermarket hull is listed, the craft must remain strictly stock, and a deck repair may not alter the original configuration by more than 2.00mm (0.08 in.). RAL.1.1, RAL.2.2

The rules do not say1 part

Four-stroke exhaust is genuinely not addressed in the Runabout Limited rules, so the Stock class answer reaches it through the inheritance rule. RAL.1.1

Governed by the parent class2 parts

Runabout Limited does not restate this part. RAL.1.1 carries every Stock class provision into Limited unless a Limited rule says otherwise, so the answer is the Runabout Stock one. RAL.1.1

Legal, with conditions1 part

Model-dependent. RAL.6.1 lets a two-stroke run modified or aftermarket carburetors, with no more venturis than cylinders and no slide type, while RAL.5.5 lets a four-stroke change only its jets, needle valves and needle valve springs. RAL.5.5, RAL.6.1

Legal, with conditions1 part

ECU may be modified OR aftermarket, provided it offers no additional inputs or outputs and uses original connections. RAL.7.2

Legal, with conditions1 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, with conditions1 part

May be rebuilt or replaced provided counterweight shape, dimensions and material type, OEM stroke, rod length and journal diameters are retained; +/-5.00% assembly weight. RAL.3.3

Legal, with conditions1 part

Aftermarket retainers with OEM springs; valves, seats, springs and pushrods may be modified or aftermarket. Titanium prohibited unless originally equipped.

Legal, with conditions1 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, with conditions1 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, with conditions1 part

Max TWO. Max 63.5mm drop - increased from Stock.

Legal, with conditions1 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, with conditions1 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, with conditions1 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, with conditions1 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.

Legal, with conditions1 part

An extension mounted on the transom counts as a trim tab, so it must be fixed in position, no wider than the planing surface and no more than 100.00mm (3.94 in.) past the end of the original planing surface, as on the fixed trim tab row. RAL.2.6

Legal1 part

Must meet USCG, SAE J-1928 Marine or UL-1111 Marine backfire flame arrester standards.

Legal1 part

A four-stroke fuel pump may be modified or aftermarket if no hazard is created, with a fuel return line fitted in the pump assembly without modifying the tank, and a two-stroke electric pump may be aftermarket up to 4 psi and must stop with the engine. RAL.5.6, RAL.6.2

Legal1 part

Modified or aftermarket filler cap allowed provided no hazard is created. The FILLER and RELIEF VALVE themselves must stay OEM.

Legal1 part

The CDI unit may be modified or aftermarket, ignition timing changed and the ignition pickup mount modified, while the original equipment charging system must stay. RAL.8.1

Legal1 part

Intercoolers may be modified or aftermarket. Mechanical intercooler pressure relief valves permitted. RAL.5.1, RAL.3.6

Legal1 part

The impeller housing, stator vane assembly, pump mounting plate and pump shoe may be modified or aftermarket but not in titanium, and the complete pump and nozzle assembly may be no more than 50.00mm (1.97 in.) longer than original. RAL.9.1

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.

IJSBA 2022, RAL, read from the rulebook on 2026-09-07. Read the rule yourself. Every IJSBA class · where the rulebooks differ · how this site reads a rulebook.

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.

What we corrected here, and when

  • Carb jet kit, needle valve, needle valve spring. Corrected 2026-10-07: this row read as not permitted, not listed in the rules, until RAL.5.5 was read against it; the clause lists these parts by name.
Cite this page

“Runabout Limited, IJSBA class rules”, BaddJet archive, https://baddjetarchive.com/legality/ijsba/runabout-limited/

Add the date you read it.

60 parts read · 23 permitted, 22 with conditions · 2022 rulebook

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