Aftermarket or modified carburetor, IJSBA

Universal constraints: no slide-type carburetors anywhere, venturi count may not exceed cylinder count.

This page is IJSBA only, and the bodies do not agree. The same part under IHRA and UIM. Which one applies to you is decided by whoever sanctions the race you enter.

Sport Spec is per-model: the same carb is legal on a Waveblaster and illegal on an HX.

Where it stands, class by class

20 classes, grouped where the same rule gives the same answer rather than listed one by one, because an answer that holds for a class usually holds for every class that borrows its rules.

What each answer below means

Not legal: This comes off. The rules refuse it in this class.
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.
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.

Not legal 5 classes

Only replaceable jets, needle valve and needle valve spring changes, choke removal and an aftermarket primer.

Fixed Steering Ski Stock · FSSK.4.2
Runabout Rec Lites · RRL.4.2
Ski Stock · SSK.4.2
Ski Lites · SKL.4.1
Runabout Superstock · RSS.5.5

Not legal 1 class

Jets, needle valves and springs and choke removal only. · RAS.5.2, RAS.6.1

Runabout Stock

Not permitted, not listed in the rules 2 classes

Not listed in this class document. Illegal under the closed-list principle.

Four Stroke Ski Lites · FSKL
Ski Modified · SKM

Legal, with conditions 1 class

ONLY ONE SINGLE CARBURETOR IS PERMITTED. · VSKL.4.1

Vintage Ski Limited

Legal, with conditions 1 class

Two-stroke aftermarket carburetors allowed. Four-stroke: jets and needles only. · RNA.5.2, RNA.6.1

Runabout Naturally Aspirated

Legal, with conditions 1 class

Polaris Hurricane and Yamaha Waveblaster carburetors may be modified or aftermarket. SEA-DOO HX MUST RETAIN STOCK CARBURETORS (rejetting and de-choking only).

Sport Spec · section headings, no numbered rules

Legal, with conditions 1 class

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

Runabout Limited

Legal 5 classes

Carburetors may be modified or aftermarket if they do not vent or spill fuel, with no more venturis than cylinders and no slide-type carburetors.

Vintage SC · VSC.4.1
Vintage X2 · VX2.4.1
Vintage Ski · VSK.4.1
Freestyle · FREST.4.1, FREST.8.4
Sport GP · SPGP.6.4, SPGP.7.1

Legal 2 classes

Carburetors may be used in addition to or instead of fuel injection, venturi count not exceeding cylinder count.

Ski Superstock · SKSS.5.4
Runabout Open / GP · ROP.5.4

Legal 1 class

Venturi count up to the number of cylinders. · SKGP.4.1, SKGP.8.4

Ski Grand Prix

Aftermarket or modified carburetor: if the rule your class applies reads differently to you, or the rulebook has changed since this was read, ask. We answer with the section we read it from, or that we have not read it. Ask a rules question.

Every IJSBA class · where the rulebooks differ · checks on parts the shop sells · how this site reads a rulebook.

Fuel · two and four stroke · legal in 12 of 20 answered, 4 with conditions