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Class Legality

IHRA · Engine

Aftermarket or modified crankshaft assembly, IHRA

IHRA answers this part for 29 of its classes. 3 of those answers permit the part outright and 4 permit it with stated conditions, leaving 22 that do not. 4 of the ones that do not are classes we read as open rather than as refusing it. 7 are inferred from how the class is written rather than quoted from a rule naming this part.

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

Where it stands, class by class

29 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

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.
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.
No rule, this is an open class
Probably keep it. The class carries no stock clause at all, so anything unlisted appears to be open. The rulebook does not say so in terms, and this is our reading rather than a permission anybody wrote down.

OEM part required 1 class

Stroke and rod length modifications permitted. · T.2.2

OEM part required 1 class

Limits: weight tolerance 5 per cent. · K.2.2

OEM part required 1 class

Four-stroke above 1600cc must maintain the original stroke (V.4.2). Limits: weight tolerance 5 per cent. · V.2.2

Legal, with conditions 1 class

No non-ferrous metals, stroke and rod length unchanged, counterweights resembling the original, and assembly weight within 5 per cent. · O.2.2

Legal, with conditions 1 class

No non-ferrous metals, the Sea-Doo HX retaining its OEM unmodified 720 flywheel, and assembly weight within 5 per cent. · U.2.2

Legal, with conditions 1 class

Model-dependent. The crankshaft of a four-stroke entry stays stock apart from bearings or shells of the original type and size (P.1, N.2.2). A two-stroke entry may rebuild its crank under O.2.2 with ferrous parts only, stroke and rod length unchanged, counterweights resembling the original and assembly weight within 5 per cent. · N.2.2, O.2.2

Legal, with conditions 1 class

Model-dependent. On four-stroke entries counterweights, stroke and rod lengths remain as the manufacturer specified and weight stays within 5 per cent, and the rulebook's wording here pulls both ways (BB.2.2). On two-stroke entries no non-ferrous metals, stroke and rod length unchanged, counterweights resembling the original with no added holes or pockets, and assembly weight within 5 per cent. · BB.3.2

Legal 1 class

Aftermarket crankshafts are permitted, where the other stock-based drag classes require the OEM crank. · DD.5

No rule, this is an open class 1 class

No restriction in section CC, and CC.1 permits any modification it does not restrict.

Aftermarket or modified crankshaft assembly: 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 IHRA class · where the rulebooks differ · checks on parts the shop sells · how this site reads a rulebook.

Engine · two and four stroke · legal in 7 of 29 answered, 4 with conditions

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BaddJet Class Legality