Mercury 35/40HP 2 Cylinder Outboards Service Manual PN 90-42794--1, Page 257Get this manual
Troubleshooting Flow Diagram Outboard falls to full down position with manual release valve closedExample a: Outboard lowers more than one tilt pin hole in eight hoursExample b: Outboard lowers during acceleration Result
Inspect Manual Release ValveResult
Manual release valve andor O-ring damageReplace defective valve and O-ringsI
Manual release valve and O-rings appear to be OKReplace O-ringsI
llnspect Memory Piston O-ring