1990 4.3 in a 20' boat, new tune up ,carb rebuilt, still cuts out and missis mostly around 2000 to 3000 rpm timing at 8 base. any ideas.

merc?

look into the hall effect in the distributor,it being a 20 yr old boat its probably on its way out..poke at it with a screw driver and see if it feels soft..they usually fall apart when you start poking at it when they are going bad.

if it looks ok ,check the coil..

yes merc 4.3 ill check what you said and let you know.

Thanks