1971 Johnson 125HP outboards Service Manual, Page 38Get this manual
7CHECKING COILUn mount coil and unscrew lead from distributor capRemount coilConnect needle type spark checking device to the coil to distributor high tension leadCrank the engine electricallySpark should jump 38" gapSee Figure 4-9If this does not occur, the coil can be checked with conventional ignition analyzerSee "Specifications" page 2-28CHECKING SENSORWith needle type spark checking device connected as shown in Figure 4-9, and key switch in "ON" pOSition, with jumper connected between and 9, separate the sensor to pulse pack connector (see Figure 4-2)Each time the connection is opened, spark should jump 38" gapIf spark jumps now, and did not in step 7, sensor requires adjustment or replacementSee "Reassembly and Adjustment of Distributor," page 4-119CHECKING TIMINGThe timing of the engine should not change during normal engine operationHowever, if the spark advance stop screw has been disturbed, the pulse pack has been replaced, or sensor adjusted, the timing should be checked as follows: aWith the timing light connected to No1 cylinder spark plug, start the engine and run at 4500 rpm (in gear)bThe 26 timing mark on the flywheel must fall in line with the timing pOinterSee Figure 4-10If necessary, move spark adjustment screw to obtain proper settingSee Figure 4-11NOTE: If major power head component has been replaced or timing pointer disturbed, check timing pointer alignmentSee "Timing Pointer Adjustment," page 4-14