7. CYLINDER/PISTON K-XCT 125i Intake Side Guide Inspect the exhaust side and intake side chain guides. Wear/Damage Replace. Exhaust Side Guide INSTALLATION Piston ring Carefully install the piston rings into the piston ring grooves with the markings facing up. Be careful not to damage the piston and rings. Do not confuse the top and second rings. To install the oil ring, install the oil ring, then install the side rails. Stagger the piston ring end gaps 120° degrees apart from each other. Stagger the side rail end gaps as shown. 7-8