Yamaha F100B F100C Outboards Factory Service Manual, Page 65Get this manual
Control systemPower trim and tilt unit Power trim and tilt unit Checking the power trim and tilt operation
1Fully tilt the outboard motor up and down few times and check the entire trim and tilt range for smooth operationCheck the power trim and tilt fluid level if necessaryNOTE: Be sure to listen to the winding sound of the PTT motor for smooth operation2Fully tilt the outboard motor up, and then support it with the tilt stop lever to check the lock mechanism of the leverWARNING
After tilting up the outboard motor, be sure to support it with the tilt stop leverOtherwise, the outboard motor could suddenly lower if the power trim and tilt unit should lose fluid pressure2Remove the reservoir cap 2, and then check the fluid level in the reservoir