UIM · Engine
UIM answers this part for 19 of its classes. 6 of those answers are permissions, with or without limits attached, and 13 are not. 5 are inferred from how the class is written rather than quoted from a rule naming this part. 5 are inherited from a parent class the rulebook points at.
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, within limits 3 classes
Cylinders may be interchanged between homologated watercraft of the SAME MANUFACTURER. Engines may be bored. No internal modification of any kind. · 501.02.03
Legal, within limits 1 class
Bored; cylinders interchanged between homologated craft of the same manufacturer. · 502.02.03
Legal, within limits 1 class
Plus machining to accept girdle system cylinder heads. · 502.03.03
Legal, within limits 1 class
Cylinders may be machined to accept girdle-system cylinder heads. If OEM cylinders do not give displacement within 10% of the maximum allowable, an aftermarket cylinder SLEEVE may be used, keeping the same port sizes and specifications as the original OEM sleeve. · 501.03.03.14
No rule, this is an open class 5 classes
No article covering this part. Free under the open-list reading of · GP1.
Aftermarket cylinder (2-stroke): 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.
Engine · two stroke · legal outright in 6 of 19