1978 Johnson 2HP outboards Service Manual, Page 17Get this manual
TROUBLE
POSSIBLE CAUSE FLOWER UNITSee Section Bent propeller (vibration) Bent or worn propeller Exhaust outlet clogged No oil Bent gear housing or exhaust housing GEXHAUST GASES ENTERING COOLING SYSTEM See Section Damaged water tube grommet or "0ring Exhaust housing to lower motor cover gasket damaged
2LOSS OF POWER(Providing Ignition OK) (continued)
3MOTOR MISFIRES (Providing
Fuel SystemCarburetor OK)