I run atf in my drive pump and 30wt in my tabs. I have a narrow boat (same as that Pokeypig dude a few posts up) its manageable, but you do need to be carefull with the tabs. Also mounting the tabs horizontal will slow there effect and make them feel more progressive.

my old 27 Excalibur was probably 1 of the narrowest hulls made for offshore
and my boat went north of 100
so trim and tabs were crutial for minimum attitude changes at higher speeds in the snot
as stated mercury made the pumps using the 24 motors to slow pump volume down for our vertical plates
instead of restricting the fluid flow and causing the pressure increase in the pump assembly
motor swap tabs moved less than 1/2 the distance when bumped or moved vrsing the other motors on 30w
before I did the motor swap I also tried 30 amp 12 to 6volt DC reducer/converters and this also slowed the pumps way down
but the high amp draw got converters hot ( they had cooling fins made in them) and I was worried 1 day a converter would fry and a tab would quit working
when put on the 24v motors never looked back,,,,,,or had to worry of frying a bandade to slow tabs down
bup,,do u do boat surveys,,,,,

I do boat surveys aka pre purchase inspections all the time.. matter of fact I was in Florida for a handful of reasons last week.. 2 boat surveys was one of those reasons.

Oct. 14 thru the 18, I will be flying to Michigan for boat repairs - one 496 and one HP 525 and one boat survey.

for any of the surveys -- I would need engine serial numbers and year models and HIN of the hull and of course as much info before I even get there so I have all my ducks in row plus what special tools to bring for the related engine sides. I have moisture meters as well and every darn marine scan tool there is on the planet among other things. On top of to add, --- I do have a pen and a clip board so I can play the part of a survey person as well, Just had to throw that in there. haha

I would love to have mine much faster! How do you speed them up?

will get with u if my bud follows through on boat purchase
to speed up is opposite of slowing down,,,,,
24 volt motor on 12 is slow
12 volt motor on 24 is really fast
also trim pumps run on higher pressure and will be faster than a tab/jackplate pump

Just a guess..maybee zero wt shock oil for hyd fluid??

How would you know if you have 12 volt or 24 volt motors already installed? are the labeled somehow? I don't recall seeing a difference on any of the trim pump motors I've ever had.

as stated mercury only used the 24v motor (as far as I know)
for the o/b Formula class 12" champ style mid for the 1" travel vertical jack built in the mid,,,
with only 1" movement needed to be slow to adjust @ 100plus
the motors look the same,,,,the only difference is the windings inside
a replacement motor by arco has the part # on it I listed earlier
but other than that ,,,,,,,tell easily by sound,,,,as 24v on 12 runs 1/2 speed of other 12v pump
i used to write on the pumps to not get them mixed in my spare parts i took to races
not many use the 24 pumps or know of except those that need real slow movement with the small rams on some tabs,,,