Timing arm

[Flyking]

I own a Yamaha 30SD 6J8. I'm reasonably sure it was manufactured in 1990. I am having issues with the timing arm sticking and I have tried lubricating it. That doesn't seem to be working. Can anyone help with what parts should be replaced? Also, when I move the arm manually I can get the RPMs up so the boat planes but it still doesn't "feel" or sound "right"