IJSBA · Driveline

Replacement wear ring, IJSBA

IJSBA answers this part for 20 of its classes. 2 of those answers permit the part outright and 13 permit it with stated conditions, leaving 5 that do not. 1 are inferred from how the class is written rather than quoted from a rule naming this part.

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.

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This is one body's answer, not the sport's. You are bound by whichever body sanctions the event you enter. If you race more than one series, build to the stricter answer. The differences are set out in the rulebook comparison.

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 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.

Not permitted, not listed in the rules 1 class

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

• Ski Modified · SKM

The rules do not say 2 classes

Not addressed in this class document.

• Vintage Ski Limited · VSKL
• Sport Spec · section headings, no numbered rules

Governed by the parent class 1 class

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

• Runabout Limited

Governed by the parent class 1 class

Not addressed in Runabout Superstock. RSS.1.1 carries every Limited class provision into Superstock unless a Superstock rule says otherwise, so the answer is the Runabout Limited one. · RSS.1.1

• Runabout Superstock

Legal, with conditions 6 classes

Permitted, subject to the limits IJSBA applies to every class, namely the sound ceiling, the hull repair tolerance, and the intake grate and sponson dimensions.

• Fixed Steering Ski Stock · FSSK
• Runabout Rec Lites · RRL
• Four Stroke Ski Lites · FSKL
• Runabout Naturally Aspirated · RNA
• Runabout Stock · RAS
• Ski Lites · SKL

Legal, with conditions 4 classes

The impeller housing may be modified or aftermarket, and the wear ring is the liner inside that housing rather than a part the document names on its own.

• Vintage Ski · VSK.6.1
• Freestyle · FREST.6.1
• Sport GP · SPGP.10.1
• Runabout Open / GP · ROP.9.1

Legal, with conditions 2 classes

The clause opens the impeller housing the ring lines to modified or aftermarket parts but bars a titanium housing, so a titanium ring is out with it.

• Vintage SC · VSC.6.1
• Vintage X2 · VX2.6.1

Legal, with conditions 1 class

Replacement wear rings within OEM INTERNAL DIAMETER specification.

• Ski Stock · SSK

Legal 2 classes

The document names no wear ring, but the impeller housing it lines may be modified or aftermarket within the 50.00mm (1.97 in.) overall pump and nozzle length limit.

• Ski Superstock · SKSS.6.1
• Ski Grand Prix · SKGP.10.1

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What we corrected here, and when

• Freestyle. Corrected 2026-10-01: this row read as unanswered until FREST.6.1 was read against it, and the clause opens the housing the ring sits in.
• Runabout Open / GP. Corrected 2026-10-01: this row read as unanswered until ROP.9.1 was read against it, and the clause opens the housing the ring sits in.
• Sport GP. Corrected 2026-10-01: this row read as unanswered until SPGP.10.1 was read against it, and the clause opens the housing the ring sits in.
• Vintage SC. Corrected 2026-10-01: this row read as unanswered until VSC.6.1 was read against it, and the clause opens the housing the ring sits in.
• Vintage Ski. Corrected 2026-10-01: this row read as unanswered until VSK.6.1 was read against it, and the clause opens the housing the ring sits in.
• Vintage X2. Corrected 2026-10-01: this row read as unanswered until VX2.6.1 was read against it, and the clause opens the housing the ring sits in.

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Replacement wear ring: 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.

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