Rough running M25XPB at low idle

[breton]

New 1999 MKII #620 28’ boat but I am concerned about rough running below 1500 rpms. i will try to get a mechanic either before or after I get the boat hauled. I changed both fuel filters before I launched. I like the way the engine pushes this boat (way faster than my Pearson 28). What do you think?
Thanks.

 

[Tally Ho]

Can you make a little movie to post of the engine idling (show the engine so we can see how much it shakes) and then rev it up until it runs smooth. It may help us understand what you are dealing with.

Greg