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IHRA · drag

Drag, Yamaha Pro Stock

IHRA 2026, DD.1. A closed-list class. The craft must stay stock except where the rules allow otherwise, so anything unlisted is not permitted.

  • 4Not legal
  • 15OEM part required
  • 16Not permitted, not listed in the rules
  • 22Legal, with conditions
  • 12Legal

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
Must start as an OEM Yamaha personal watercraft. Backdating between models of the same family is permitted, for example FZR to FZR or FX to FX. No model-year list is published.
Displacement limit
No displacement ceiling. Eligibility is by manufacturer.
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 (4)

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.

  • Section DD states that anything not listed is not legal, and this class is a bullet list. Applied literally that makes every unmentioned component illegal, including ones the general technical regulations at section J expressly permit on all classes. Which of the two governs is not stated.
  • The supercharger bullet contradicts itself. It permits front and rear housings to be OEM or aftermarket, requires an aftermarket housing to meet OEM specification with no modification, and then requires gearing AND housings to remain OEM and unmodified. Both halves are printed and neither is withdrawn. DD.3 carries the equivalent bullet with only the gearing restricted and no contradiction.
  • This class says exterior bumpers are not required, where I.17 requires a permanently affixed nose bumper on every craft not originally built without one. Section DD never says it overrides section I, so a safety requirement and a drag allowance sit against each other unresolved.
  • The rulebook names Hydrodrags staff and Hydrodrags Garmin units inside DD without saying what relationship Hydrodrags has to IHRA.

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 class criteria of any kind. No hull dimensions, no displacement ceiling, no sound limit.
  • No cooling article.
  • No ignition timing article.

What the rules say (69 parts)

12 permitted outright, 22 permitted with stated conditions, 4 refused by a rule we can quote, 15 held to the original part by a rule we can quote and 16 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

Nitrous oxide is not permitted, and neither is a turbocharger unless the craft came with one. DD.1

Not legal1 part

DD.1 allows hull work only forward of the intake grate, so nothing may be added at the rear of the hull. DD.1

OEM part required1 part

Must remain OEM and interchangeable between WaveRunner models, with vacuum fittings, upgraded throttle body spacers and ribbon deletes permitted. DD.1

OEM part required1 part

No aftermarket supercharger is listed in DD.1, so the unit stays the one the craft came with: its impeller OEM and unmodified, its gearing OEM with no re-gearing, and no older centre gears on Yamaha models to change the OEM ratios. Within that unit DD.1 allows aftermarket shafts and rebuild kits, and lets front and rear housings be OEM or aftermarket to OEM specification before saying in the same bullet that housings must remain OEM and unmodified. DD.1, DD

OEM part required1 part

Yamaha Pro Stock starts from an OEM craft and keeps its hull, so no replacement hull may be fitted, and the work DD.1 allows on it is answered under hull modification. DD.1

OEM part required1 part

No modifications. Existing holes must be replaced with OEM uncut panels. Center wall may be removed. Exterior bumpers not required. DD.1

OEM part required1 part

Modifications permitted but no open holes. If originally two seats, both must be installed. DD.1

Not permitted, not listed in the rules16 parts

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

Legal, with conditions1 part

Waterbox must be retained; aftermarket permitted with a through-hull exhaust pipe. STRAIGHT PIPES NOT PERMITTED. DD.1

Legal, with conditions1 part

One aftermarket electric IN-TANK pump only. External or mechanical pumps not allowed. DD.1

Legal, with conditions1 part

Fuel pressure regulators and upgraded fuel lines are permitted, alongside the single in-tank electric pump. DD.1

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

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

Must meet OEM specifications. Oversized valves NOT allowed. DD.1

Legal, with conditions1 part

Impeller must be OEM and unmodified. Housings OEM or aftermarket meeting OEM spec with no modifications. Gearing and housings OEM and unmodified. No re-gearing. Yamaha may not use older center gears to alter OEM ratios. Aftermarket shafts and rebuild kits permitted. DD.1

Legal, with conditions1 part

May be replaced within OEM specifications. J.18.3

Legal, with conditions1 part

FX intake grates must use the OEM mounting bolt location and bolt pattern. DD.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). DD.1, 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

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. DD.1, J.16

Legal, with conditions1 part

The seat must be OEM with no open holes, and both seats fitted where the craft had two, but modifications are permitted, read here as taking in a replacement cover. DD.1

Legal, with conditions1 part

DD.1 says exterior bumpers are not required, while I.17 requires a permanently affixed nose bumper on every craft not originally built without one, and section DD never claims to override section I, so ask the series before removing anything. DD.1, 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

Under the general maintenance allowance a cooling hose or clamp may be aftermarket, and DD.1 keeps the jet pump stock except for its water fittings; no other fitting is named. J.7, DD.1

Legal, with conditions1 part

Work is confined to the area forward of the intake grate, and the hull may be neither split nor lightened. A cut through the hull may be repaired only from outside on an FZR or FZS, and inside and out on a GP, VXR or FX. Where fitted the centre wall may come out, and hull and top deck are joined by rivets, bolts, adhesive or an equivalent. DD.1

Legal1 part

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

Legal1 part

Aftermarket intercoolers are permitted, with no size, type or mounting limit stated. DD.1

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, DD.1, 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.

Cite this page

“Drag, Yamaha Pro Stock, IHRA class rules”, BaddJet archive, https://baddjetarchive.com/legality/ihra/drag-yamaha-pro-stock/

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69 parts read · 12 permitted, 22 with conditions · 2026 rulebook

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