1979 Johnson 2HP Outboards Service Manual, Page 17Get this manual
CAUSE 2LOSS OF POWER(Providing Ignition (continued) FLOWER UNITSee Section Bent propeller (vibration) Bent or worn propeller Exhaust outlet clogged No Bent gear housing or exhaust housing GASES ENTERING COOLING SYSTEM GSee Section Damaged water tube grommet or ring Exhaust housing to 10wer motor cover gasket damaged SP PL UGSee Section Cover or inner terminal damaged (spark plug terminal out of H.T.lead) Faulty lead Loose10w torque Incorrect heat range Defective (cracked insulator) MAGNETOSee Section Incorrectly adjusted points Loose wiring or condenser damaged (loose) Fiber breaker block worn Points dirty or pitted Defective breaker Loose armature plate screws or worn armature plate liner ADJUSTMENT Incorrect tilt ang1e VENTILATION Protruding hull attachments too 10ng Transom too high Improper 10ad distribution Marine growth bottom Added weight (water absorption) Hook in bottom Mis-matched boat and motor (boat under-powered)
MISFIRES (Providing Fuel SystemCarburetor
4POOR PERFORMANCE ON (Providing motor is running