1998 Johnson Evinrude "EC" 9.9 thru 30 HP 2-Cylinder Outboards Service Manual, Page 40Get this manual
AnodesTesting and Replacement Erosion or disintegration in salt or brackish water indicates the anodes are performing their functionThe anodes should be inspected at intervals and replaced, when necessary, or corrosion of the engine will increase
INote If any anode
OJ Test for proper installation of the anodeCalibrate an
has been reduced to 03 its original size (113 eroded), it must be replaced!