Trim not moving evenly
#1
Registered
Thread Starter
Trim not moving evenly
As the title says, all mercury stuff, but the port side moves faster than the starboard side. Is there a way to adjust the pressure on the pumps to make them trim out more evenly?
TIA
Mike
TIA
Mike
#2
Check if both pumps have similar length battery cables, positive and ground. Good chance the slower pump has lower "operating" voltage from more voltage drop across the cables. Hose lengths and over-tightened/crushed flare seats, the small ones in particular, can raise operating pressures during trim too.
Pump maximum pressure can be adjusted internally, but that may not fix the issue because the pump doesn't usually reach maximum pressure until the cylinders reach full travel. There are different rate pumps (different height gear pumps), but if the pumps are original Bravo pumps, they should be the same and should be set to the same maximum pressure.
Pump maximum pressure can be adjusted internally, but that may not fix the issue because the pump doesn't usually reach maximum pressure until the cylinders reach full travel. There are different rate pumps (different height gear pumps), but if the pumps are original Bravo pumps, they should be the same and should be set to the same maximum pressure.
#3
Registered
it could also be a tight cyl on the slow side. run all way up and clean shafts with really fine paper. 600 or 1000 grit. you might need one or two cylinders. rebuild is pretty easy if housing isn't too corroded up. could also swap pumps and see if slowness switches sides.
#4
Registered
Put the battery switch in "Both" position and see if they trim closer to the same speed.
#5
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Thread Starter
#6
Registered
Thread Starter
Check if both pumps have similar length battery cables, positive and ground. Good chance the slower pump has lower "operating" voltage from more voltage drop across the cables. Hose lengths and over-tightened/crushed flare seats, the small ones in particular, can raise operating pressures during trim too.
Pump maximum pressure can be adjusted internally, but that may not fix the issue because the pump doesn't usually reach maximum pressure until the cylinders reach full travel. There are different rate pumps (different height gear pumps), but if the pumps are original Bravo pumps, they should be the same and should be set to the same maximum pressure.
Pump maximum pressure can be adjusted internally, but that may not fix the issue because the pump doesn't usually reach maximum pressure until the cylinders reach full travel. There are different rate pumps (different height gear pumps), but if the pumps are original Bravo pumps, they should be the same and should be set to the same maximum pressure.
#7
Registered
not necessarily. if trim cyls are tighter on one side, they will put heavier load on that pump and cause greater voltage drop. but start with the cheapest-easiest thing and clean all big wire terminals. ESPECIALLT both ends of the ground wire from trim pump to block. batt wire from block to neg terminal is prolly not an issue or it wouldn't crank motor. pump ground can also be straight to neg batt terminal.