1976 Evinrude 200 HP Outboards Service Manual, PN 5199, Page 55Get this manual
ROUGH RUNNING ENGINE A rough running engine may be due to interaction of the Power Packs because of faulty isolation diode in Power PacksThe diode may be checked by using an ohmmeter set to high ohms scaleCheck each Power Pack as follows: aDisconnect the leads from Power Pack terminals #6 and #11See Figures 4-17 and 18bConnect the ohmmeter leads between the #6 and #11 power pack terminalsNote meter readingcReverse the ohmmeter leads and note readingAn infinite (very high) reading in both directions indicates the diode is openA low ohms reading in both directions (approximately 100 ohms) indicates shorted diodeA normal diode will read resistance in one direction and infinite reading in the other directiondIf diode is defective, replace Power Pack
Connect between power pack terminals and 11 for isolation diode test (rough running engine)
Figure 4-17Port Side Power Pack Sensor Leads as Indicated by Broad Arrows
CHECKING SENSOR COIL