Not permitted, not listed in the rules 12 classes
On a closed list an unlisted modification is not permitted. · A.2.2, J.1
IHRA · Fuel
Carburetor jets, needle valves and springs, IHRA
IHRA answers this part for 29 of its classes. 0 of those answers permit the part outright and 13 permit it with stated conditions, leaving 16 that do not. 3 of the ones that do not are classes we read as open rather than as refusing it. 16 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 and UIM. 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
- 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.
- 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.
Not permitted, not listed in the rules 1 class
DD.7 states no engine type, so a two-stroke entry cannot be ruled out, and DD.7 does not list this part, so under the DD preamble it is not legal on either engine. · DD.7
Legal, with conditions 4 classes
Only the jets, needle valves and springs replaceable, the choke removable and an aftermarket primer allowed, and nothing else on the carburetor may be changed.
- Runabout Lites · AA.3.2
- Runabout GP2 · Y.3.2
- Runabout GP3 · Z.4.2, Z.5.1
- Ski Lites · O.3.1
Legal, with conditions 1 class
Model-dependent. Polaris Hurricane, Yamaha WaveBlaster 701: Aftermarket permitted. U.3.1 Sea-Doo HX: Stock carburetors; jetting and de-choking allowed. · U.3.1
Legal, with conditions 1 class
Only the jets, needle valves and needle valve springs replaceable, the choke removable if it creates no extra air intake, and an aftermarket primer allowed, and nothing else on the carburetor may be changed. · M.2.2
Legal, with conditions 1 class
Model-dependent. A two-stroke entry may run modified or aftermarket carburetors with no more venturis than cylinders and no slide type, while a four-stroke entry follows Four Stroke Ski Lites, which lists no carburetor change. · P.1, P.2.4
Legal, with conditions 1 class
Model-dependent. A two-stroke entry may run modified or aftermarket carburetors with no more venturis than cylinders and no slide type, while a four-stroke entry may only replace the jets, needle valves and needle springs and remove the choke. · BB.4.2, BB.5.1
Legal, with conditions 1 class
No slide-type carburetors, and no more venturis than the engine has cylinders. · T.3.1
Legal, with conditions 1 class
Slide-type carburetors NOT allowed. · S.3.1
Legal, with conditions 1 class
No more venturis than the engine has cylinders, and carburetors may be run with or instead of injection. · CC.3.1
Legal, with conditions 1 class
Venturi count must not exceed cylinder count and slide-type is prohibited, and four-stroke entries may run carburetors alongside or in place of EFI. · V.3.1, V.5.1
Legal, with conditions 1 class
Carburetors may be modified or aftermarket and run alongside or in place of fuel injection, with no more venturis than cylinders and no slide type. · X.3.1
No rule, this is an open class 3 classes
The class states only what it bans and calls itself run what you brung, against a section DD preamble that says anything unlisted is illegal.
- Drag, 2 Stroke Unlimited · DD.12
- Drag, Stand Up Unlimited · DD.10
- Drag, Unlimited · DD.6
Carburetor jets, needle valves and springs: 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.
Fuel · two and four stroke · legal in 13 of 29 answered, all with conditions