Johnson Service Bulletin SB-917 - Piston Ring Compressing Tools
Issued August 25, 1962, this bulletin introduced four full-circle piston ring compressors for Johnson 28, 40, 50 and 75 HP outboard engines. It explains why automotive-style compressors could damage pistons and rings and illustrates the recommended installation procedure.
Bulletin SB-917 - Special tools
August 25, 1962
SUBJECT: Piston Ring Compressing Tools: Part #309917 - 28 H.P. engines Part #308866 - 40 H.P. engines Part #308479 - 50 H.P. engines Part #308867 - 75 H.P. engines.
Piston ring tension on 28, 40, 50 and 75 H.P. engines is such, that ring compressing tools are required when installing pistons in cylinders of these engines.
Automotive type ring compressing tools have been tried on outboard engines but do not guarantee perfect alignment of the ring gap and piston dowel pin. A general occurrence from use of automotive type ring compressors is damaged pistons and broken piston rings.
To assist in field repair work, we have recently designed the subject ring compressing tools. These tools are all currently available from Outboard Marine Corporation Parts Depot at the following net prices.
When properly used, these new ring compressing tools will eliminate possible damage to the pistons and rings. Valuable repair time can also be saved through the use of proper tools.
SB-917 Page 2
Figures 1 and 2 illustrate proper use of the subject tools -
Oil pistons and rings thoroughly.
Slip piston ring compressor over piston skirt (fig. 1) with tapered end of compressor facing rings. Align ring gap with dowel pin. Press piston into ring compressor. DO NOT HAMMER.
Insert piston skirt into cylinder bore (fig.2). Hold ring compressor firmly against top of cylinder - align piston deflector - press piston into cylinder.
The above ring compressors are for standard size pistons only.
DO NOT ORDER THESE ITEMS FROM JOHNSON MOTORS OR FROM YOUR PARTS DISTRIBUTOR.
Mail all orders with prepayments to:
OUTBOARD MARINE CORPORATION PARTS DEPOT P.O. BOX 470 GALESBURG, ILLINOIS
JOHNSON MOTORS Richard C. Cooper Service Department
RC:eb
NOTE: Post on your Miscellaneous index.
Original 1962 special tools order form
The original detachable order form is reproduced below as a historical reference.
