1973 Evinrude Norseman 40 HP Service Manual, Page 13Get this manual
TROUBLE CHECK CHART (CONT) TROUBLE POSSIBLE CAUSE ASPARK PLUGSSee Section Cover or inner terminal damaged (spark plug point out of H.Tlead) Faulty leads Looselow torque Incorrect heat range Defective (cracked insulator) BMAGNETOSee Section Incorre_ ctly adjusted points Loos wiring Coil or condenser damaged (loosFibre breaker block worn Points dirty or pitted Sheared fl ywheel key POOR PERFORMANCE ON BOAT AINCORRECT PROPELLER Incorrect tilt angle Incorrect fuel mixturptoo much lubricant(smoking) Remote controls incorrectly adjusted Propeller hub slipping Bent or worn prope ller Exhaust outlet damaged Bent gear housing or exhaust housing (broken driveshafts) Altitude horsepower loss Catamaran (single engine)venturi effect Exhaust leaks Overheating BCAVITATION Protruding hull attachments Keel too long Bent propeller (vibration) Transom too high CBOAT Improper load distribution Marine growth on bottom Added weight (water absorption) Hook in bottom ASTARTING CIRCUITSee Se ction Loose or corroded battery connections Safety switch inoperative (loose) Throttle advanced too far Poor or broken battery connections Weak or shorted battery Defective key or starter switch Jammed starter drive Damaged starter drive parts Worn brushes Broken brush spring Open circuit in solenoid Burned commutator Broken field terminal Shorted or open windingsarmature or field BEXCESSIVE STARTER CURRENT DRAWSee Section Worn or dry armature shaft bearings Excessive friction in engine Brushes not seating Dirty or corroded com mutator Loose pole pieces Shorted armature or field Bearing heads buckled