STUDI KASUS PERMASALAHAN UMUM DAN PENANGANAN KERUSAKAN MESIN PADA SEPEDA MOTOR KAWASAKI NINJA 150 R DI BENGKEL SPESIALIS DUA TAK

Abstract

This case study aims to identify the common problems occurring in the engine of the Kawasaki Ninja 150 R, a 148 cc two-stroke sport motorcycle equipped with Super KIPS (Kawasaki Integrated Power-valve System) technology, and to analyze the diagnostic procedures and repair steps applied by mechanics at a two-stroke specialist workshop. Although production of this model has been discontinued, it remains widely used in Indonesia and requires technical handling that is distinct from four-stroke motorcycles. This research used a descriptive qualitative method with a case study approach. Data were collected through semi-structured interviews, direct observation of the repair process, and documentation of service cases at a two-stroke specialist workshop in Purworejo. The results show that the common problems in the Kawasaki Ninja 150 R engine are centered on three main systems: (1) the Super KIPS system, which frequently jams due to carbon deposits from combustion residue, causing a loss of performance at medium to high engine speed; (2) the radiator cooling system, which is disrupted by poor coolant circulation, damaged water pump seals, or a blocked radiator, and can lead to overheating; and (3) the side lubrication oil system, which malfunctions when the oil pump does not work optimally or the oil channel is blocked, risking piston scoring and engine seizure. Diagnosis was carried out systematically through symptom identification from the user, visual inspection, component disassembly, and root-cause analysis. Repairs were carried out by cleaning carbon deposits from the KIPS components, replacing the coolant and damaged water pump parts, and clearing the side oil channel according to the manufacturer's recommendations.