1976 Johnson 2HP 2R76 Outboard Motor Service Manual, Page 16Get this manual
TR OUB LE CHECK CHART
TROUBLE 1MOTOR WILL NOT START POSSIBLE CAUSE AFUEL SYSTEMSee Section Fuel shut-off valve not opened Fuel vent screw not open Speed control not advanced (throttle closed) Engine flooded Old fuel Clogged fuel filter Choke not closing completely Fuel system faulty BIGNITION SYSTEMSee Section Cam or linkage improperly adjusted Inverted breaker cam Sheared flywheel key Ignition system faulty APOWER HEADSee Section Carburetor and magneto not synchronized Air leak at manifold gasketswarped manifold (backfires) Broken leaf valves (backfires) Excessive carbon on pistons and cylinder head Stuck piston rings, or scored cylinder, or piston BCARBURETORSee Section Poor fuel mixtoo much lubricant (oil) Carburetor adjustment(too leanbackfires) (too richexcessive fuel) Choke not operating properly Air leaks at packing nuts or core plugs Inlet needle and seat worn or sticky Boss gasket damaged Incorrect carburetor float setting Altitude horsepower loss CFUEL TANKSee Section Faulty fuel line Fuel tank or filter plugged Fuel line restricted Fuel vent screw not open Fuel shut-off valve restricted DEXHAUST GAS ENTERING CARBURETORSee Section Exhaust cover screws leaking Cover plate gasket damaged Exhaust relief obstructed Lower bearing housing gasket leaking Cracked exhaust housing Lower bearing housing screws loose EOVERHEATING POWER HEADSee Section Exhaust cover gasket leaking Power head gasket improperly installed or damaged Head gasket leaking (warped cylinder head) (water in cylinder) Water intakes obstructed Pump cover air bleed restricted Water passages or tube obstructed Pump impeller damaged Pump impeller plate worn Pump impeller cup worn Water tube improperly installed Impeller cover grommet leaking FLOWER UNITSee Section Bent propeller (vibration) Bent or worn propeller Exhaust outlet clogged Bent gear housing or exhaust housing