10-12 SERVICING INFORMATION Complaint Symptom and possible causes Remedy Engine overheats Defective engine internal parts 1. Heavy carbon deposit on piston crowns Clean. 2. Not enough oil in the engine Add oil. 3. Defective oil pump or clogged oil circuit Replace or clean. 4. Sucking air from intake pipes Retighten or replace. 5. Use incorrect engine oil Change. 6. Defective cooling system See radiator section. Lean fuel/air mixture 1. Short-circuited IAP sensor/lead wire Repair or replace. 2. Short-circuited IAT sensor/lead wire Repair or replace. 3. Sucking air from intake pipe joint Repair or replace. 4. Defective fuel injectors Replace. 5. Defective ECT sensor Replace. Other factors 1. Ignition timing is too advanced due to defective Replace. timing advance system (ECT sensor, GP sensor, CKP sensor and ECM). 2. Drive chain is too tight. Adjust. Dirty or heavy 1. Too much engine oil in the engine Check with inspection E exhaust smoke Lwindow, drain out excess oil. 2. Worn piston rings or cylinders P Replace. 3. Worn valve guides Replace. 4. Scored or scuffed cylinder walls Replace. 5. Worn valves stems M Replace. 6. Defective stem seal Replace. A 7. Worn oil ring side rails Replace. S Slipping clutch 1. Weakened clutch springs Replace. 2. Worn or distorted pressure plates Replace. 3. Distorted clutch plates or pressure plates Replace. Dragging clutch 1. Some clutch spring weakened while others Replace. are not. 2. Distorted pressure plates or clutch plates Replace. Transmission will 1. Broken gearshift cam Replace. not shift. 2. Distorted gearshift forks Replace. 3. Worn gearshift pawl Replace. Transmission will 1. Broken return spring on shift shaft Replace. not shift back. 2. Rubbing or stickily shift shaft Repair or replace. 3. Distorted or worn gearshift forks Replace. Transmission jumps 1. Worn shifting gears on driveshaft or Replace. out of gear. countershaft 2. Distorted or worn gearshift forks Replace. 3. Weakened stopper spring on gearshift stopper Replace. 4. Worn gearshift cam plate Replace.