June 12, 1961
Bulletin No. SB-852
Trade accessories.
SUBJECT: Engine hour meter connected thru ignition switch;
40 h.p. models RDS & RDSL-22 thru 23
75 h.p. models V4S & V4SL-12 thru 13C;
75 h.p. models V4A & V4AL-13, 13C & 13F.
In response to questions concerning the advisability of connecting engine hour meters
through the ignition switches on the subject electric starting engines, we advise this
can be accomplished without harm provided the very simple connection instructions are
accurately followed.
This bulletin is based on an engine hour meter which performs very satisfactorily. It
operates on a principle similar to that of automotive electric clocks with a duty cycle
of 2½ minutes. At the start of each duty cycle the meter draws about six-tenths (.6)
of an ampere which is a very small amount of current consumption. The described meter
is the "Hobbs Engine Hour Meter" manufactured by the John W. Hobbs Corporation,
Springfield, Illinois. Because the meter is not available from the factory nor Outboard
Marine Corporation's Parts Depot, we refer you to the John W. Hobbs Corporation for
further information, prices, availability, etc. Both standard and flush mounting types
are available for both six (6) and twelve (12) volt electrical systems. The meter is
guaranteed by the manufacturer, so the factory assumes no liability whatever in respect
to this trade accessory.
CONNECTIONS AT SWITCH: The Hobbs Engine Hour Meter can be used on any electric starting
Johnson engine which uses a switch having a "hot" terminal when the switch is in the "ON"
position.
Magneto equipped engines: Examination will reveal that switches used on magneto equipped
engines during 1960 and 1961 have five (5) terminals. One of these is marked with the
letter "A" (accessory), and must be used to connect the hour meter. Because the
negative (-) terminal of the battery is grounded in all Johnson electrical systems, the
Hobbs Engine Hour meter must be connected as follows:
ENGINE MODELS USES SWITCH NO.
1961 - 40 h.p. RDS & RDSL-23 378326
1961 - 75 h.p. V4S & V4SL-13 & 13C 378326
1. Connect red meter wire to "A" terminal (accessory) of switch.
2. Connect black meter wire to gray wire marked
"Tachometer Ground Lead", OR
3. If a tachometer is installed, connect black meter wire to the
same tachometer terminal to which the gray tachometer ground
lead has been connected.
ENGINE MODELS USES SWITCH NO.
1960 - 40 h.p. RDS & RDSL-22 & 22C 278186 or 378326
1960 - 75 h.p. V4S & V4SL-12 & 12S 278186 or 378326
1. Connect red meter wire to "A" terminal (accessory) of switch.
2. Connect black meter wire to red choke wire under dashboard,
(identified with white, plastic tag).
over