1978 Johnson 4HP outboards Service Manual, Page 82Get this manual
dInstall special tool and rotate flywheel clockwise just enough to turn starter pulley about 112 turns against spring tension to pre-load springRemove tool while holding pulleyeRelease rope end and feed thru hole in lower motor coverPull rope out as far as it will goWhile holding rope fully extended, grasp spring end loop and pull spring out of cup and stop assemblyPre-load on spring is acceptable if from to 18 inches (20-45 cm) of spring can be pulled outSee Figure 7-11Pre-load is determined by more or less turns on pulley before rope end is released from pulley as described in step "D Adjust as necessaryf If pre-load is correct, install rubber bumper, rope handle, and knot ropeSee Figures 7-1 and 7-6Adjust idler gear engagement as described in "Adjustment