Johnson Service Bulletin SB-954 - 75 HP Leaf Valve Service

Issued May 10, 1963, this bulletin announced that individual leaf valve components for certain V-75 engines would be discontinued as distributor stock ran out. Johnson instructed dealers to use complete leaf valve assembly 377889 instead.

Johnson Motors gray Service Bulletin letterheadFactory photograph of complete leaf valve assembly 377889
May 10, 1963
#SB-954 Carburetion
SUBJECT: DISCONTINUANCE OF DETAIL SERVICE - 75 H.P. LEAF VALVES.
Engines affected: Models V4S(L)-12 and up Models V4A(L)-13 and up
Your Parts Distributors stock of the following detail parts will be exhausted in the near future.
307126 - Leaf Plate 307128 - Leaf Valve 307127 - Leaf Stop 308947 - Leaf Valve
As this occurs, it will be necessary to order #377889 LEAF VALVE ASSEMBLY (Shown in figure 1) whenever one of the above detail parts is required for service.
This new method of servicing 75 H.P. leaf valves will eliminate mis-assembly of the valve to the leaf plate in the field which results in below par performance. It will also insure that the leaf stop (307127) and leaf plate (307126) are replaced in event of leaf valve breakage. The mere replacement of a broken leaf valve is not always a lasting repair, since in some cases an irregularity in the leaf stop may have been the actual cause of valve breakage. Quite often a broken leaf valve will also damage the leaf plate after several hours operation, in such a way as to result in failure of the replacement valve after a short period of time.
FIG.1 - #377889 Leaf Valve Assem.
Continue ordering the above detail parts from your distributor until his supplies of these detail parts are exhausted. Then begin ordering the complete assembly.
Sincerely,
JOHNSON MOTORS
Robert Compton Administrative Assistant Service Dept.
RC:eb NOTE: Post on your V-75 index.

Parts reference

Complete leaf valve assembly 377889 replaces individual servicing of leaf plate 307126, leaf stop 307127, and leaf valves 307128 and 308947, once remaining distributor supplies are exhausted. Applies to V4S(L)-12 and later and V4A(L)-13 and later models.