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Class Legality

IHRA · sport

Sport Spec

IHRA 2026, U. A closed-list class. The craft must stay stock except where the rules allow otherwise, so anything unlisted is not permitted.

  • 3Not legal
  • 5OEM part required
  • 15Not permitted, not listed in the rules
  • 31Legal, with conditions
  • 10Legal

Read out of the published IHRA rulebook on 2026-09-11, so confirm anything that decides a purchase. The full note is at the foot of the page.

Running the class

Eligible craft
Kawasaki X2 pre-2005, Kawasaki X2 2005 to 2007, Sea-Doo HX, Yamaha WaveBlaster 701 and Polaris Hurricane.
Displacement limit
1mm overbore (U.2.1). The class criteria state no displacement ceiling. Eligibility is by model list, and the only capacity control in the section is a 1 mm overbore cap.
Licence or tier
Not stated.
Minimum weight
Not stated.

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 (2)

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.

  • U.5.3 prints "a 11 drive ratio" for what is plainly 1:1. A transcription defect.
  • U.4.1 makes aftermarket Yamaha CDI legality turn on whether the craft uses 760 cylinders and on whether timing can be manually adjusted. Which specific units satisfy that is a question about products the rulebook does not name.

Sections this rulebook does not contain for this class

Confirmed absent by a targeted read rather than merely unnoticed. In a closed-list class an absent article is why a part reads as not permitted; in an open class it is why one reads as open.

  • No displacement ceiling. The class is controlled by a model list and a 1 mm overbore cap instead, and it is the only non-drag class with no capacity figure.
  • No forced induction article.

What the rules say (64 parts)

10 permitted outright, 31 permitted with stated conditions, 3 refused by a rule we can quote, 5 held to the original part by a rule we can quote and 15 refused by our reading of the class rather than by a quoted rule. 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.
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.

Not legal1 part

Bolts, nuts and washers may not be substituted with titanium unless originally equipped. Locking mechanisms are allowed. J.7

Not legal1 part

Titanium driveshafts are prohibited by name, where Ski Vintage permits them. The rulebook states both and reconciles neither. U.5.2

Not legal1 part

U.5.1 bars any hull extension attached to the transom. Only fixed trim tabs, answered on their own row, may reach past the hull, by up to 100 mm (3.94 in). U.5.1

OEM part required1 part

U.5.3 keeps the stator vane assembly OEM stock and names no aftermarket impeller housing. The housing changes it allows are OEM ones: an OEM plastic housing on the Sea-Doo HX with the small-diameter hub and vane count kept, and the factory-superseded six-vane pump on the Polaris Hurricane. A Kawasaki X2 may fit aftermarket pump cones, and the pump and nozzle assembly may grow by no more than 50 mm. J.1, U.5.3

OEM part required1 part

The original seat base must stay in use. The cover may be replaced, but seat height may change by no more than 12.7 mm either way and the cover may add no more than 12.7 mm. U.6.1

OEM part required1 part

The hull may be repaired but not otherwise modified, and a repair may not move it more than 2 mm (0.08 in) from its original configuration. J.1, J.13

Not permitted, not listed in the rules15 parts

On a closed list an unlisted modification is not permitted. A.2.2, J.1

Legal, with conditions3 parts

Model-dependent. On the Kawasaki X2 pre-2005, the X2 2005 to 2007 and the Yamaha WaveBlaster 701, WET-STYLE SYSTEMS ONLY, with dry-type systems and water-jacketed chambers prohibited and no tuned portion outside the hull. Electronic water injection is prohibited on all models. On the Sea-Doo HX the stock exhaust and water box must be unmodified, with no spray bars, stinger sprayers or water injectors, factory water routing and no bypass systems, and larger bolts or studs allowed. U.2.3

Legal, with conditions1 part

An aftermarket flame arrester is allowed if it meets USCG, UL-1111 or SAE J-1928 Marine standards. U.3.2

Legal, with conditions1 part

Yamaha CDI aftermarket allowed if timing cannot be manually adjusted; Yamaha units NOT using 760 cylinders may use programmable ignition. Kawasaki Gen2 (2005-2007) CDI may be programmable. Original charging systems required. Timing may not be advanced at the stator plate. U.4.1

Legal, with conditions1 part

Gauges may be modified or removed provided no hazard is created and any resulting hole is sealed. Section J permits modification and removal and never addresses adding an aftermarket instrument. J.15

Legal, with conditions1 part

J.7, in the general rules for every class, names wiring as replaceable with aftermarket options, which overrides the closed-list default and covers replacement wiring. Connectors are not named on their own, and J.7 does not open added inputs or outputs, a different harness design or an ECU. J.7

Legal, with conditions1 part

Must retain original port timing, dome profile, skirt length and shape, material type. Limits: weight tolerance 5 per cent, max port chamfer 1 mm, max chamfer angle 30 degrees. U.2.1

Legal, with conditions1 part

Repairs are allowed for a crack or puncture, but only one damaged area affecting one cylinder bank. No other modification. J.11

Legal, with conditions1 part

Yamaha WaveBlaster may upgrade to 701 62T style cylinders; pre-1996 may update to 1996+ components; Yamaha 760 cylinders allowed subject to U.4.1 ignition restrictions. Cylinders may be machined for girdle-system heads. Limits: max overbore 1 mm. U.2.1

Legal, with conditions1 part

On the Kawasaki X2 pre-2005, the X2 2005 to 2007 and the Yamaha WaveBlaster 701 drop-down domes are prohibited, with maximum compression 190 lb and minimum squish clearance 0.04 in. On the Sea-Doo HX drop-down domes are prohibited, with maximum compression 175 lb and minimum squish clearance 0.051 in. U.2.4

Legal, with conditions1 part

May be replaced within OEM specifications. J.18.3

Legal, with conditions1 part

Aftermarket or modified, full-length type with at least one bar parallel to the driveshaft, dropping no more than 12.00mm (0.47 in) below the flat plane of the pump intake. J.18.1

Legal, with conditions1 part

Aftermarket or modified. An extension may not exceed the width of the original plate, and on a ski may not extend more than 100 mm (3.94 in). J.18.1

Legal, with conditions1 part

Replacement trim plates may be used provided they mimic the handling characteristics of the stock plates. J.18.2

Legal, with conditions1 part

Aftermarket fixed-position tabs only, with manual and automatic tabs and transom hull extensions prohibited, extending no more than 100 mm. U.5.1

Legal, with conditions1 part

Braking devices may be disabled for safety, and reverse buckets and trim motors may be removed or modified to disable them, provided no hazard is created. J.18.4

Legal, with conditions1 part

Aftermarket, modified, repositioned or removed. Up to two, each no longer than 36 in (91.45 cm), protruding no more than 3.94 in (100 mm) horizontally, at least 6 mm thick with radiused leading edges, and not attached to a planing surface. J.16

Legal, with conditions1 part

OE seat base must remain in use, with height change and cover thickness each limited to 12.7 mm. U.6.1

Legal, with conditions1 part

Mat kits and padding are allowed in every class by the general rules (J.14), which overrides the closed-list default. Footholds and foot straps are not named there, so they stay not permitted. J.14

Legal, with conditions1 part

On the Kawasaki X2 models this class admits, the pole and its mounting brackets can be changed or swapped for aftermarket parts if the steering still works as it did, and the pole can be lengthened or shortened with its mount strengthened; the other eligible craft have fixed handlebars. J.17.2

Legal, with conditions1 part

Replacement bumpers and side rails may be used provided they create no hazard. A permanently affixed nose bumper remains required. J.13, I.17

Legal, with conditions1 part

May be added to adjust handling. Constant mass only, and no other part may be modified to carry it. J.19

Legal, with conditions1 part

Model-dependent. A cooling hose may be replaced with an aftermarket one under the general maintenance allowance, and Kawasaki, Polaris and Yamaha craft may add cooling fittings. The Sea-Doo HX must keep its factory stock water routing with no additional bypass systems. J.7, U.5.3, U.2.3

Legal1 part

Aftermarket fuel tanks are allowed, provided the tank is securely fitted without creating a hazard, in a closed fuel system that never vents or spills. U.3.3

Legal1 part

J.7, in the general rules for every class, names hoses and clamps as replaceable with aftermarket options, which overrides the closed-list default and covers an aftermarket fuel hose. Fittings are not named on their own. J.7

Legal1 part

May be replaced, as may starters and oil injection systems, with the oil injection system removable or disconnectable. J.8

Legal1 part

Impellers may be altered or aftermarket, while the stator vane assembly must stay OEM stock. U.5.3

Legal1 part

Grips, throttle and cables may be modified or aftermarket. The bar must be padded at the mounting bracket or the crossbar padded. J.17.1

Legal1 part

Steering shaft, holder, handlebar holder and cables may be aftermarket, and quick-turn modifications are allowed. J.17.2

Legal1 part

The bilge pump may be modified or disconnected and aftermarket bilge draining systems are permitted, provided they create no hazard. J.10

IHRA 2026, U, read from the rulebook on 2026-09-11. Read the rule yourself. Every IHRA 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

  • Aftermarket handle pole. Corrected 2026-10-07: the Sport Spec row called the part not applicable to a seated class; the class admits the Kawasaki X2, and J.17.2 applies to every class.
  • Footholds, foot straps and tray mats. Corrected 2026-10-02: the Sport Spec row read the closed-list default and refused a mat kit, which J.14, in the general rules for all classes, allows.
  • High-pressure fuel line and fittings. Corrected 2026-10-02: the Sport Spec row read the closed-list default and refused a fuel hose, which J.7 allows in every class; until 2026-10-31 this line wrongly excepted the drag section, where J.7 applies too.
Cite this page

“Sport Spec, IHRA class rules”, BaddJet archive, https://baddjetarchive.com/legality/ihra/sport-spec/

Add the date you read it.

64 parts read · 10 permitted, 31 with conditions · 2026 rulebook

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