I've been seeing 17cc domes for sale for 250r's. What are they and what do they do? Are they like cool heads. And why are they called 17cc? Do they raise the displacement by 17cc's?
Thanks

 

They are the interchangable domes that go with the Coolhead. The 17cc is, and someone correct me if im wrong, the size of the combustion chamber when the piston is at top dead center. There are different sized dome to produce different compression levels by changing the size of the combustion chamber.

------------------
Jayson Blough '99 Banshee, '97 Warrior, '96 Blaster Yes I like Yamaha