Indmar Assault Whining Noise

[dducray]

I have a 2003 Launch SSV with Indmar Assault 5.7L engine. There is a loud whining noise from the engine, especially when the engine is hot and idling. I took it to a dealer and they think it is the fuel injectors and ruled out a bad bearing or belt. They told me that the entire carb would have to be replaced and that the injectors that are integrated into the carb/throttle body and they cannot be replaced. They said the injectors are clean so that isn't the issue. Has anyone had this problem and experience fixing it?

[DAFF]

Buy a small stethoscope with the wire probe on the end of it. Bring the boat to the lake drive it around till you hear the sound. Then with the probe rest it on the engine in several locations and listen closely to the pitch and tone of the sounds. In time you will narrow the sound to a region.... From here you can make an educated guess where the whine is originating from.

[dducray]

The dealer techs said that they used a stethoscope to track the sound to the injectors. I asked if they could replace the injectors and they said that the injectors could not be removed and recommended replacing the carb for $980.

[Meyeronfire]

The dealer techs said that they used a stethoscope to track the sound to the injectors. I asked if they could replace the injectors and they said that the injectors could not be removed and recommended replacing the carb for $980.

I just replaced both fuel injectors on my 03 Launch, I have the same 5.7 320HP EFI Indmar assault, Replaced both myself went to NAPA auto parts matched with a 93 chevy silverado 79$ a piece very simple to replace. Unplug the electronic wiring components, take the torc heads off (8 I think) pull old injectors out, make sure you pay attention to how they come out, replace with new ones, replace o rings and gaskets, replace throttle body, do not overtighten torc screws.

Im wondering if the ethonol in the fuel these days has anything to do with injectors dying quicker than they should?