power tilt and trim

My tilt and trim started jerking when I lowered it in the water the other day it trimed out fine and goes up fine any ideas

thanks

sorry its a 1998 evinrude 150 intruder

I hope you get it fixed because it is aggravating. My Johnson 150 has been doing that for some time now and have tried everything I hear to do. I hope its nothing expensive to fix.