1968 Evinrude Starflite 100 HP outboards Service Manual, Page 34Get this manual
Engine missing or surging may also be caused by insufficjent, contaminated or excessive fuelAfter determining that this condition is not caused by carburetion, proceed (in order listed) to check the ignition systemA malfunctioning vacuum switch may prevent engine from starting or cause erratic operationSee paragraph "Vacuum Switch 1WIRINGCheck all wiring associated with the system for any loose or corroded terminal connections and plug-in connectionsMake sure of clean, tight connection from the negative (-) terminal of the pulse transformer to ground at the voltage regulatorAlso check for clean, tight battery ground cable connectionCheck all high tension leads for cracked or oil soaked insulationThe high tension leads should also be checked with an ohmmeter to locate any excessive resistance or opensCheck for correct battery polarity (negative ground)Make sure battery cable connections are clean and tight
Figure 4-4Advance Adjustment Screw NOTE There is also triangular timing mark on the flywheelSee Figure 4-3If this mark is used, connect timing light to No2 cylinder spark plug3SPARK PLUGSThe spark plugs should be removed and examinedIf the center electrode has worn to point where it is below the ceramiC, it should be replacedNaturally, any plug which has cracked insulator or shows other signs of damage should be replacedSee Figure 4-5