Not legal1 part
Bolts, nuts and washers may not be substituted with titanium unless originally equipped. Locking mechanisms are allowed. J.7
- Titanium fasteners · Engine
IHRA · runabout
IHRA2026, X. A closed-list class. The craft must stay stock except where the rules allow otherwise, so anything unlisted is not permitted.
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.
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.
48 permitted outright, 15 answered by our reading of the class rather than by a quoted rule, 0 the rules do not settle. Grouped by the answer, because an open class gives one answer to most questions and printing it once per part would say the same sentence forty times.
Not permitted, not listed in the rulesOur reading, not a rule we can quote at you. This class requires the craft to stay stock except where the rules allow otherwise, and this part is not on the list.
Not legal1 part
Bolts, nuts and washers may not be substituted with titanium unless originally equipped. Locking mechanisms are allowed. J.7
OEM part required1 part
Original casting matching the engine block must be used. X.2.6
Not permitted, not listed in the rules15 parts
On a closed list an unlisted modification is not permitted. A.2.2, J.1
Legal, within limits2 parts
Valve count must remain unchanged. Tuned portion must not extend beyond the hull. Exit may move to the transom below the bond flange. X.2.5
Legal, within limits1 part
Butterfly count must not exceed cylinder count. X.3.3
Legal, within limits1 part
May increase fuel flow but must not increase airflow into the chamber. Extra injectors allowed. X.3.5
Legal, within limits1 part
Automatic shutoff is required and manual on/off pumps are prohibited. X.3.5
Legal, within limits1 part
Must be OE; replacements may come from another PWC if unmodified. Fully aftermarket only with Race Director or Technical Director approval. Filler and relief valve must remain OE unaltered. X.3.4
Legal, within limits1 part
SAE J30R9 required. Metal filters on the high-pressure side. X.3.5
Legal, within limits1 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, within limits1 part
Boring and stroke modifications allowed within displacement limits. X.2.1
Legal, within limits1 part
Repairs are allowed for a crack or puncture, but only one damaged area affecting one cylinder bank. No other modification. J.11
Legal, within limits1 part
Must originate from a production runabout watercraft. Only limitation is the cc limit. Interchanging top decks and engines permitted. X.2.7
Legal, within limits1 part
Method of activation must remain unchanged. X.2.8
Legal, within limits1 part
May be replaced within OEM specifications. J.18.3
Legal, within limits1 part
Limits: max assembly extension 50 mm. X.6.4
Legal, within limits1 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, within limits1 part
Limits: max rear extension 7 in. X.6.1
Legal, within limits1 part
Replacement trim plates may be used provided they mimic the handling characteristics of the stock plates. J.18.2
Legal, within limits1 part
Fixed, automatic or rider-controlled, extending no more than 3.94 in. X.6.2
Legal, within limits1 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, within limits1 part
Aftermarket hulls permitted if approved by the series organizer. Upper deck must resemble the OEM version as closely as possible. Silhouette test settles disputes. X.7.1
Legal, within limits1 part
Sufficient flotation must be maintained. X.7.5
Legal, within limits1 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, within limits1 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, within limits1 part
May be added to adjust handling. Constant mass only, and no other part may be modified to carry it. J.19
Legal2 parts
Aftermarket permitted. X.5.1
Legal2 parts
Aftermarket permitted. X.4.1
Legal1 part
The air intake system may be modified or replaced. X.3.2
Legal1 part
Battery charging circuit may be disabled or removed entirely. X.5.2
Legal1 part
Aftermarket permitted. X.4.3
Legal1 part
Relocation allowed. X.5.3
Legal1 part
Named in the general maintenance allowance along with wiring, hoses and clamps. J.7
Legal1 part
May be replaced. J.8
Legal1 part
Limits: weight tolerance 5 per cent. X.2.2
Legal1 part
Aftermarket permitted. X.2.2
Legal1 part
Aftermarket permitted. X.2.8
Legal1 part
May be replaced, as may starters and oil injection systems, with the oil injection system removable or disconnectable. J.8
Legal1 part
Full circulating water-jacket housing required while running. May be added to an originally NA four-stroke. X.4.1
Legal1 part
Aftermarket permitted. X.4.2
Legal1 part
Aftermarket permitted. X.6.4
Legal1 part
1:1 ratio. X.6.3
Legal1 part
Aftermarket permitted. X.7.3
Legal1 part
Aftermarket permitted. X.7.2
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
Aftermarket permitted. X.2.3
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, X, read from the rulebook on 2026-09-11, not verified by a racer. Read the rule yourself, Runabout GP. Every IHRA class · where the rulebooks differ.
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.
65 parts read ยท 48 permitted outright ยท 2026 rulebook