The vibration begins at 1100 rpm and gets worse all the way up to 2600-2700 RPM. I have a fixed prop. The weird thing is that all is perfect on the way out for a sail and then coming back in once I fire her back up it's vibration city!Sean- I assume you have checked your shaft alignment- is the vibration at a certain rpm range ? I get a vibration between 24-2600 on my engine- not bad but noticeable from other rpm ranges. Do you have a folding or feathering prop that perhaps is not fully deploying. Or I guess a fixed prop could be unbalanced but I am only taking a SWAG here- I am not a very good diagnostician but those would be my thoughts-