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 · ski
IHRA2026, S. 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.
41 permitted outright, 19 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
Not permitted, not listed in the rules19 parts
On a closed list an unlisted modification is not permitted. A.2.2, J.1
Legal, within limits3 parts
Manifold, head pipe, water box, expansion chamber, muffler. Exit may relocate to the transom but must not extend beyond the hull. S.2.5
Legal, within limits2 parts
Slide-type carburetors NOT allowed. S.3.1
Legal, within limits2 parts
No input, output or sensor may be added to the unit. S.4.1
Legal, within limits1 part
Manual pumps prohibited. Limits: max 4 psi. S.3.3
Legal, within limits1 part
Fuel fillers must come from another OEM watercraft. S.3.3
Legal, within limits1 part
Covers only. S.4.3
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
Must fit the original battery box and be securely fastened. J.9
Legal, within limits1 part
Must remain OEM except: port modifications, internal surface changes, ignition/stator mounting area for aftermarket ignition, extra carb pulse-line fittings, drain removal or plugging. S.2.3
Legal, within limits1 part
May be modified or replaced with an aftermarket part. The original diameter must be maintained in Stock class, and the rulebook never defines which classes that is. J.18.2
Legal, within limits1 part
May be replaced within OEM specifications. J.18.3
Legal, within limits1 part
Titanium impeller housings and stator vane assemblies allowed. Limits: max extension from transom 139.7 mm. S.5.2
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
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, 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
The inner hull liner or deck CAN be modified to facilitate foam removal - opposite of Ski Modified. S.6.3
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
The handle pole assembly and mounting brackets may be modified or replaced provided original functionality is retained. Length may be altered and the attaching point reinforced. J.17.2
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
Legal1 part
Aftermarket permitted. S.3.2
Legal1 part
RPM limiter may be bypassed. Total-loss ignition systems allowed. S.4.2
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
Ring number, type, and placement may be modified. S.2.1
Legal1 part
Limits: weight tolerance 5 per cent. S.2.2
Legal1 part
Aftermarket permitted. S.2.7
Legal1 part
Aftermarket permitted. S.2.6
Legal1 part
May be replaced, as may starters and oil injection systems, with the oil injection system removable or disconnectable. J.8
Legal1 part
1:1 ratio. TITANIUM DRIVESHAFTS ALLOWED in this class. S.5.1
Legal1 part
Titanium driveshafts are allowed in this class, as are titanium impeller housings and stator vane assemblies. Nothing else in titanium is, and the J.7 fastener ban still stands. S.5.1, S.5.2
Legal1 part
Aftermarket permitted. S.6.1
Legal1 part
Aftermarket permitted. S.6.4
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. S.2.4
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, S, read from the rulebook on 2026-09-11, not verified by a racer. Read the rule yourself, Ski Vintage. 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.
61 parts read ยท 41 permitted outright ยท 2026 rulebook