yamaha reverse gear problem

[dogsbollox0]

My 2001 yamaha 9.9 high thrust does not like reverse gear,on low revs she will not move when i ncrease the revs she moves but there is a lot of vibration,the best results are acheived by giving it short bursts of higher revs,forward gear does not seem to have a problem.
could this be a shot hub or something more serious.

[Ken]

dogs,
Sure sounds like a spun hub, but it should be slipping in forward also. I would take it to a prop shop and have it checked out.
Good luck,
Ken K