i have set my shift cables according to directions on merc-stuff.my trouble is that when i shift on land and watching the interrupt switch it is making and breaking without any load on the drive.just sitting still.i have to touch it with my finger to get it back to nuetral spot.i replaced the cable last year with little use.could the switch spring wire have lost tension or is there to much tightness in the cable.it doesnt pull very hardin or out.i know there is a lot of variables here.any thoughts