Johnson Service Bulletin SB-782 - Connecting Rods

May 19, 1960. Johnson Motors explains why three variations of connecting rod 277205 can be used interchangeably in 15 HP models FD-10 through FDEL-10S.

Johnson Motors Service Bulletin letterhead
May 19, 1960
Bulletin No. SB-782
SUBJECT: CONNECTING RODS - 15 H.P. Models FD-10 thru FDEL-10S.
Factory photographs comparing three 15 horsepower Johnson connecting rods
A
B
C
Pictured are three (3) connecting rods, all of which are identified by the same part number, 277205. These rods are used interchangeably on 15 H.P. engine models FD-10 through FDEL-10S.
Note that the wrist pin ends of the rods vary in wall thickness and also that the shank of rod 'A' has an additional rib along each side giving it a heavier appearance. These differences do not affect interchange- ability or engine performance.
When installing these rods, matching them is advisable but is not absolutely essential. The added weight of rod 'A' over rods 'B' or 'C', or rod 'B' over rod 'C' is not critical and constitutes no particular cause for alarm.
JOHNSON MOTORS
W. W. DeWees
W. W. DeWees Service Department
WWD:eb