this is exactly what i was worried about with a single trim switch for twins. such as on zero effort type throttles. one switch-two drives with diff trim speeds = a boat going across the water listed...i just picked up some new throttles for twins and it came with the single switch set up...

Mine were doing it on my old Formula. I pulled the pump motors off and found corrosion on the commutators where the brushes ride. After cleaning both with a brass brush they both ran the same speed, easy fix.

+1

yes look for some of the age/wear & tear concerns before messing with the pressure valves (although some great info in this thread).

Mine were off a bit and it turned out to be a bad ram, finally got so it wouldn't go down at all, changed it out, now both are back at the same speed.