I hit a submerged log with my boat last year and ripped the drive completely of the transom. I put all new trim pistons, lines, and a pump on. I cycled the trim up and down several times and it works fine. My problem is when the boat is at speed the trim wont go up, when I stop and am at idle it has no problem. I believe I have all the air out of the system. Any help would be appreciated, I am stumped.

My guess is that you have the lines reversed. Make sure that when you put power to the Blue wire the drive goes up.

Does it go up and down on the trailer but not under load??

if so, 1. the pump has the relief valve on the wrong side or the pump is wired backwards and you need to fix it and switch the lines....

A key indicator that you have them reversed is when you hit the trim down button and the drive is all the way down, does the motor strain??? If it sounds like its under a lot of pressure and the motor speed slows down, that's your problem..

When you trim in, as soon as the drive is in the down position the bypass should kick in and if everything is reversed you wont be able to trim the drive up at speed cause you're activating the bypass.

As far as the wiring goes, remember "blue sky" and "green ground"... Blue wire is up, green is down and the blue wired solenoid should be on top, green bottom.

This may not be the issue but something to check out.

I dont remember the pump straining when I put the trim down all the way, but I havent tried it since I put it away last winter. When this originally started I had the original pump in the boat and hadnt touched the wiring. I then bought a new pump thinking it was the problem. Maybe the old pump was bad and then I crossed the lines on the new one? I will check this week. Thanks for the help!

My guess

I checked the wiring today and it is correct. I also checked the lines they are also in the correct place. A friend of mine said that maybe one of the rams is bad, they are new though. Any other thoughts as to what the problem could be?

Bad o ring in the trim cylinder !!!!!!!

sounds like you may have effed up your valving or seals in your trim pump when you hit the log,reverse pressure from the impact could have done it..

I have bought a new pump and it didnt help. Im going to have the rams pressure tested, they are new but were probably made in china.

I went through this a couple of years ago, replaced pump, rebuilt cylinder and found out I didn't have the manifold hooked up correctly from the lines entering it (the 2 lines that you can't see). My advice would be to switch the connections at the pump to make sure that it isn't that. Wiring doesn't make a difference assuming the direction is right.

There are several connections that could be reversed on the pressure lines (at the pump, at the manifold (six connections, 2 out of sight), at the rams). I have also seen manufacturers add an extension to the lines in the engine compartment in case the pump is not located on the transom. If you have swapped the pump, it sounds like either the rams or the connections are the cause.

The down-side of the pump has enough force to lift the drives on when the boat is on the trailer, but is about 1000psi less than the up-side - meaning you could have all good parts and just need to switch the lines around.