2003 ST 4 Stroke 9.9/15HP Johnson outboards Service Manual, Page 145Get this manual
POWER UNIT CYLINDERCRANKSHAFTPISTON
IACAUTION I
When installing the spacer, do not allow the two ends to overlap in the groove1st ring and 2nd ring
CORRECT
1st ring and 2nd ring differ in ring face shape
Install: 2nd ring 1st ring
Ring direction Position the mark on the 2nd ring to the piston head side Reinstall the 1st ring to the original direction There is no IDmark on standard size 1st ring