Johnson Service Bulletin #915 (1962) - Throttle Control Shaft Wear

Factory service correction for Johnson 50 HP and 75 HP V-4 outboards. Bulletin 915 identifies excessive throttle-control shaft wear caused by metal-to-metal contact and recommends replacement sleeve 307841 and washer 305831, plus OMC Type A Lube.

Johnson Motors blue seahorse Service Bulletin letterhead
August 24, 1962Bulletin No. 915
SUBJECT: Throttle Control Shaft Wear -
         50 h.p. V4(SL) 10 thru 11B
         75 h.p. V4S(L) 12 thru 14B
         75 h.p. V4A(L) 13 thru 14
Factory Figure 1 showing throttle control linkage and part numbers 304352, 305894, 305831 and 307841
FIGURE 1

Occasionally there is evidence of excessive wear on the throttle control shaft which is being caused by the magneto/distributor control link. This condition can occur on any of the subject engines.

Apparently the retaining spring (arrow, fig.1) has a tendency to force the link against the control shaft which in time tends to wipe the lubrication from between these two surfaces. This results in metal to metal contact, and wear becomes evident.

Whenever this condition exists on any of the subject models, we suggest discarding the original sleeve and washer (part #304352 and #305894, fig. 1) replacing them with the new style sleeve and washer (part #307841 and #305831, fig. 1). The new style sleeve includes a nylon flange which when installed on the control shaft link pin, as shown in figure 1, prevents metal to metal contact of the control shaft and link. The thin washer (305831) is necessary for proper clearance to avoid binding. It is further recommended that this connection be thoroughly lubricated with OMC TYPE A LUBE prior to assembly.

JOHNSON MOTORS
Service Department
Service Department
RC:eb

NOTE: Post on your V-50 and V-75 indexes.

Factory part numbers

304352 and 305894: original sleeve and washer. 307841 and 305831: revised sleeve and washer. Lubricate with OMC Type A Lube.