Alpha won’t trim underway

[Tominator88]

Hello, new to me boat 87 241 offshore alpha 1 260 hp
My Outdrive goes right up when stopped but wile cruising I can’t get it to trim up at all if I stop raise it then drive it will stay up I replaced pump unit with anouther used one with no difference all my the power wire and jumper to solenoids are new the ground is good I’ve been through it all so many times and gotten nowhere I have no leaks so I didn’t suspect the pistons but they seam like the only thing left I put the drive up it stays up for weeks I jump up and down on it it doesn’t budge any suggestions? Btw I’m pretty good at/experienced backyard mechanic all the soilanoids sesm to be working properly all my wires are correct size anchor tin coated with heat shrink crimps done this year thanks in advance

 

[Bondo]

Ayuh,.... Is the trim pump motor running when you trim up, while under way,..??..??
You should be able to hear it,....

 

[Tominator88]

I thought it was I felt like somthing just didn’t have the power

 

[Scott Danforth]

is the pump plumbed and wired correctly?

green (grass) - drive should go down
blue (sky) - drive should go up.

the pump is set for 2900 psi up, about 900 psi down.

if its plumbed/wired backwards, it wont have enough power to overcome the thrust of the prop.

if you raise the drive a bit and then take off, does it stay in position? if not, then the seals in the rams are toast.

 

[Tominator88]

Thanks that is very interesting I will check that out it does stay up if I left it wile stopped then go thanks I had place else to check

 

[stresspoint]

try using the trailer switch and see what happens "" don't over trim as that will happen easily with he trailering button".

 

[Tominator88]

So I finally got to go test my setup to see if I had fires/hoses switched I put a test light on solanoid and it lights up when I hit up and when I hit down any thoughts?

 

[Bondo]

So I finally got to go test my setup to see if I had fires/hoses switched I put a test light on solanoid and it lights up when I hit up and when I hit down any thoughts?

Ayuh,..... Does the pump run up,..??

 

[Tominator88]

It does go up and it goes down could it be getting a small amount of stray voltage from the motor it the weirdest thing the test light lights up wile going up and going down and the drive is going up and going down and no I’m not on the constant hot side of soilanoid

 

[stresspoint]

It does go up and it goes down could it be getting a small amount of stray voltage from the motor it the weirdest thing the test light lights up wile going up and going down and the drive is going up and going down and no I’m not on the constant hot side of soilanoid

did you try the trailer switch to see what happens ???? .

 

[Tominator88]

The trailer switch has already been bypast the throttle switch does it all and I have no trim indicator

 

[Bondo]

It does go up and it goes down could it be getting a small amount of stray voltage from the motor it the weirdest thing the test light lights up wile going up and going down and the drive is going up and going down and no I’m not on the constant hot side of soilanoid

Ayuh,.... It sounds like it's working as it should, so I guess the next step is to test it while running under power,....

 

[Scott06]

Hello, new to me boat 87 241 offshore alpha 1 260 hp
My Outdrive goes right up when stopped but wile cruising I can’t get it to trim up at all if I stop raise it then drive it will stay up I replaced pump unit with anouther used one with no difference all my the power wire and jumper to solenoids are new the ground is good I’ve been through it all so many times and gotten nowhere I have no leaks so I didn’t suspect the pistons but they seam like the only thing left I put the drive up it stays up for weeks I jump up and down on it it doesn’t budge any suggestions? Btw I’m pretty good at/experienced backyard mechanic all the soilanoids sesm to be working properly all my wires are correct size anchor tin coated with heat shrink crimps done this year thanks in advance

It would seem that the thrust of the prop is over coming the ability of the cylinder to hold? I would try to disconnect the cylinders and see if you can push them in while the trim is off. I had one of my cylinders bleed down like this , couldn't even hold the drive up when I was put drive back on after maintenance. Other cylinder was fine and wouldn't move.

Would think either the piston seals in the cylinders are passing or if there is valving in the pump to keep the fluid from backflowing when not in use ?