Mercury 35/40HP 2 Cylinder Outboards Service Manual PN 90-42794--1, Page 209Get this manual
Power Trim General Information Description
The Power Trim system consists of an electric motor, pressurized fluid reservoir, pump, two trim cylinders, and one tilt ram The remote control (or trim panel) is equipped with switches that are used fortrimming the engine "up" and "down," and for tilting the engine for shallow water operation (at slow speed) or for "trailering The engine can be trimmed "up" or "down" while engine is under power or when engine is not running
Operating "Up" circuit will actuate the "up" solenoid (located under engine cowl) and close the electric motor circuitThe electric motor will drive the pump, thus forcing automatic transmission fluid thru internal passageways into the "up" side of the two trim cylindersThe two trim cylinders working together will position the engine at the desired trim angle within the 20 maximum trim rangeThe Power Trim system is designed so the engine cannot be trimmed beyond the 20 maximum trim angle as long as engine RPM is above approximately 2000 RPMThe engine can be raised beyond the 20 maximum trim angle for shallow water operation, etc by keeping the engine RPM below 2000 RPM If engine RPM increases above 2000 RPM, the thrust created by the propeller (if deep enough in the water) will cause the trim system to automatically lower the engine back to the 20 maximum trim angleTRIMMING ENGINE "DOWN" ("IN")