UIM · Fuel
The tuning tier that stays legal in the closed-list classes.
19 classes, grouped by the answer rather than listed one by one, because an answer that holds for a class usually holds for every class that borrows its rules. 5 of them publish no component rules of their own and are marked below; for those, the link to the parent class is read from the categories table rather than stated in the rulebook.
No rule, this is an open class Our reading, not a rule we can quote at you. This class carries no stock clause at all, so anything unlisted appears to be open. The rulebook does not say so in terms.
Governed by the parent class 8 classes
No component rules are published for this class and no single parent class is named, so this part cannot be answered for it. That is an absence in the rulebook, not a permission.
Legal 3 classes
Replaceable-type jets, needle valves and needle valve springs may be changed; choke may be removed provided it creates no additional air intake. · 501.02.04.01
Legal 2 classes
Explicitly permitted by this class.
Legal 1 class
502.02.05-01
No rule, this is an open class 5 classes
No article covering this part. Free under the open-list reading of · GP1.
Carb jet kit, needle valve, needle valve spring: 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 UIM class · where the rulebooks differ · signed checks on parts the shop sells.
Fuel · two stroke · legal outright in 6 of 19