Engine stalling at idle

[Reliablerose]

I have a 92 sea ray with a mercruiser alpha one I/O. This summer I have had a continuing issue of the engine stalling out when at idle. Boat runs fine otherwise on the water. Odd thing is that I have run it serval times out of the water with water muffs and the engine is fine at idle. Gas is good. Just replaced the distributer cap, spark plug wires, and ignition coil. Could this be an exhaust issue? Any ideas??
Ben

 

[Bondo]

Ayuh,...... Welcome Aboard,...... Which motor,..?? Carbed, Efi, or Mpi,..??

Got a serial number for the motor,..??

 

[Reliablerose]

Thank you! It’s a 4.3LX V6 thunderbolt IV. It has a carburetor I believe.
Ben