low speed engine noise in new Mercury 60 HP 4 Stroke

by Skip
(Phoenix)

We just purchase a new Mercury 60 HP 4 stroke for our pontoon boat.

It has a loud squealing/grinding noise that starts at 1700 RPM and completely goes away again at 2700 RPM.

We have taken it back to the dealer but it won't make the noise with the "ears" on only on the lake. They took our boat to the lake and said they couldn't hear it.

It is a speed we much go a lot in the "no wake" zones and it is loud enough to be very irritating, hard to hear the radio.

Has anyone else had the problem?