All ADA Racing billet heads are made from 6061-T6 aluminum and CNC machined in-house for consistency and performance. The head shell is then anodized for durability and protection against salt-water corrosion.
This listing includes the head shell, O-rings that fit into the head shell grooves, aluminum spacer washers, and brass fittings.
For reference, the stock head is equivalent to 46cc domes.
For ’99 models with stock carbs, you need to check your serial# for the correct ignitor. If the serial# is KAW44000 or lower then you need the 44cc dome for premium pump gas. If the serial# is KAW44001 or higher then you can use the 42cc domes for premium pump gas.
Please Note: ADA Racing billet heads/domes use standard reach NGK ES spark plus (BR8ES or BR9ES) depending on compression. Higher compression requires colder spark plugs (BR9ES). This can also depend on ignition timing.