: 28mm (with aftermarket up-sizing options scaling from 32mm to 36mm) [1.14].

: For detailed technical breakdowns and part numbers (useful for DIY repairs), the Y16ZR Parts Catalogue is available for download. Key Maintenance Areas for the Y16ZR

The heart of the Y16ZR is its liquid-cooled, 4-valve, SOHC engine with Variable Valve Actuation (VVA). The updated service manual provides specific procedures for servicing this unique valvetrain. Valve Clearance Adjustments

The request for the "UPD" version is often the first sign of a serious mechanic. Newbies ask, "How do I change my oil?" Veterans ask, "Does anyone have the link for the UPD service manual? My link is dead."