1971 Johnson 4HP Outboard Motors Service Manual, Page 30Get this manual
usedWithout the use of test equipment, coi1s, condensers, point assemblies replaced needlesslywide variety of ignition analyzers is available from various manufacturersIn addition, some automotive testers having the specifications can useduse of the Graham, Merc-O-Tronic, Stevens ignition analyzers is particularly mended, since these units have provisions for checking all functions of the ignition systemSee Figure4-22Detai1ed instructions for the use of any tester provided with the unit; therefore, only general information is given components of the ignition system should checked, even though placing part seems to have corrected the troubleFor example, replacing points have increased spark, further improvement might realized if condenser is found to weak and is replacedCOIL TESTING The c.ail is tested under conditions of actual tion, as the ignition analyzer provides an interrupted primary current and measures the induced secondary voltageSee Coil Specifications, Section 2If the coil is in good condition and is suitable for use, the induced secondary voltage, as indicated the meter, will fall within the green ("Good") with primary current adjusted as specifiedmust removed from the armature plate for this testConnect the test leads from the ignition analyzer to the making sure that the black lead is connected to the ground lead of the the red lead to the breaker point lead, and the high tension lead to the secondaryWith the index adjusted as specified, note the meter readingSee Figure 4-9low reading the tester indicates weak coi1 replacedNo attempt should made which must to improve this spark increasing primary current; the is defective if it cannot made to give good reading the specified primary currentcompletely dead is indicated if there is reading Check for leakage from the (caused moisture, cracks in the housing, carbon paths) running the test the outside of the Replace any which shows any leakageSee Figure 4-10