1972 Johnson 2HP Outboard Motor Service Manual, Page 26Get this manual
4-3 hasten the collapse, condenser in the primary circuit absorbs the current which would otherwise across the opening breaker pointsrapid collapse induces current sufficient voltage in the secondcircuit to across the spark plug air gapcondenser, which acts like storage tank, consists thin sheets metal foil separated insulation, rolled to save space and enclosed in metal caseOne sheet foil is grounded to the case, the other is connected through an insulated wire to the insulated stationary breaker pointSPARK PLUGS Spark plugs having the heat range very important peak operation the motorThis motor is designed to operate with J6J spark plugsSpark plugs classified according to the temperatures at which they designed to operate, COLDSee Figure 4-2Selection the correct spark plug depends the type service to which it is subjectedUnless the spark plug is properly suited to the motor, trouble arise which might interpreted as carburetor difficultyVery low trolling speeds will tend to plugs due to the oil not burning the However, at full throttle with hotter plug, the operating temperature too high, resulting in ignitionAn extreme temperature range will difficult to control with one plugSpark plugs furnished with the motor selected average serviceSpark plugs recommended the HP Model 1Champion: 2J6J Figure 4-2Hot and Cold Plugs Figure Condenser Exploded RUBBER INSULATOR INSULATION