IJSBA · Exhaust

Through-hull exhaust outlet / relocation kit, IJSBA

Relocation to the transom below the bond flange is the usual form.

This page is IJSBA only, and the bodies do not agree. The same part under IHRA. 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 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 1 class

Relocating the exhaust is prohibited and the exit opening may not exceed 2 inches. · VSKL.3.7

• Vintage Ski Limited

Not legal 1 class

Exit location unchanged, opening size unchanged.

• Runabout Naturally Aspirated · RNA

Not legal 1 class

Exhaust must remain stock as supplied by the manufacturer. Only a stinger insert and cooling lines are allowed. · SKL.3.6

• Ski Lites

Not permitted, not listed in the rules 6 classes

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

• Fixed Steering Ski Stock · FSSK
• Runabout Rec Lites · RRL
• Ski Stock · SSK
• Four Stroke Ski Lites · FSKL
• Runabout Stock · RAS
• Ski Modified · SKM

Legal, with conditions 1 class

Exit may be relocated to the hull rear; outlet flap may be removed.

• Sport Spec · section headings, no numbered rules

Legal, with conditions 1 class

Through-hull flap may be removed; the exit may not be relocated. · RAL.4.7

• Runabout Limited

Legal 8 classes

Through-hull exhaust modified or aftermarket; exit may be relocated to the transom below the bond flange.

• Ski Superstock · SKSS.3.8
• Vintage SC · VSC.3.7
• Vintage X2 · VX2.3.7
• Vintage Ski · VSK.3.7
• Freestyle · FREST.3.7, FREST.7.8
• Ski Grand Prix · SKGP.3.7, SKGP.6.8, SKGP.7.8
• Sport GP · SPGP.4.8, SPGP.5.9
• Runabout Open / GP · ROP.4.8

Legal 1 class

The exhaust system may be aftermarket providing a hazard is not created. · RSS.3.13

• Runabout Superstock

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Through-hull exhaust outlet / relocation kit: 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.