1986+ Mercury 6/8/9.9/10/15HP 2-stroke Factory Service Manual, Page 255Get this manual
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10Secure detent spring to block with boltsSpring may have slotted holesInstall spring so that it is raised UP and at end of slot travelTorque bolts to 2.8 Nm (25 lbin11Secure end of shift shaft to yoke of horizontal shift shaft with couplerRotate coupler until it locks in place