April 10, 1961
Bulletin No. SB-
Electrical System
(Supplement to SB-813)
SUBJECT: Tachometers for battery ignition systems;
75 h.p. models V4A & V4AL-13 & 13C
Paragraph five (5) of Service Bulletin #SB-813 on the subject of
alternator equipped engines informed you that tachometer leads were
provided for operating battery ignition type tachometers, and that
magneto-type tachometers would not work on these engines. Because
the gray tachometer lead is connected to the negative primary
terminal of the ignition coil, tachometers installed for alternator
equipped engines must be designed to operate off the primary circuit
of the ignition system.
While there are many brands of tachometers available, the factory is
not in a position to recommend specific models of specific brands.
Therefore, if you have not already done so, we suggest contacting
tachometer suppliers and/or manufacturers to request specific in-
formation as to which of their tachometers operates off the primary
circuit of 12-volt battery ignition systems.
JOHNSON MOTORS
W. W. DeWees
W. W. DeWees
Service Department
WWD:eb
NOTE: Post on your V-75 index.
WAUKEGAN, ILLINOIS