I just bought a X135 and I put it on the front of my bass boat all of that was easy. but when I moved my x51 from the trolling motor to the dash I started haveing problems, the hard part was when I had to run the xducer form the back of the boat to the console, I just dont see how to do it. Im sure theres a way.

A Fishtape is pretty much a must and some loss of religion will probably come about before you finish. Just be carefull feeding the fishtape and pulling xducer connector. If it hangs, don't just try tugging it through, you will regret that. Tape up the hooked end on the fishtape before you start feeding it through.

Feed the fishtape from under the console to the rear of the boat. Use plenty of black tape to tape the connector to the fishtape so there is a bullet shaped cone in front of the connecter. This will help greatly in getting it to feed back through when you start pulling. It also helps sometimes to have two people, one pulling the fishtape and one feeding the coax.

As way2slow said, when taping the xducer connector to the fishtape, or wire coat hanger (that works for me) use as much tape as necessary to remove any edges where the tape and connector meet so when you're feeding the thing through it's less likely to hang.  

Most production boats have some sort of tube or pipe that most of the wiring runs through to the back of the boat.  It's normally up under the gunwale on the drivers side right around where your throttle is locate and the other end is some where back at the upper rear corner of the boat.  You can either feed it through that or try and find openings between the rear and the front and slowly work it through the hull that way.

Good luck.