With my motor in gear at idle speed when I tilt the motor down it is not a smooth action. I guess you could call it jerkie almost like it is falling a little bit at a time. When I get to the trim range it is a nice smooth movement.
Could it be that the fluid level is low ?
And if the fluid level is low what do you use to fill it and how do you fill it ?
I see slotted plug on what looks like the fluid reservoir for the trim and tilt. I would assume that you fill it there with the pump that you fill the lower unit ?