whistle from engine
 

I'm getting a whistle (sounds like a vacuum line) Only does it at around 1500 to 2000 rpms. Pretty sure it's not the belt. It's brand new, tight, and the sound doesn't sound like a squeal.

The block was just replaced because the previous owner burned it up. It's a 6.2 Liter black scorpion. Has about 13 hours on it now.

On another note, the boat dies if I throttle it up and let off too quickly. I have to slowly back it off. Any ideas on this as well?

There is a small muffler in a hole in the throttle body. Its a useless part so to speak but when you remove them on the mercs you get a whistle/hissing noise. Check and see if it has been removed.

As for the stalling could be an iac or anything for that matter. Best to put it on a scanner and have it checked. The merc systems can tell you ALOT off of the computer and while it may not tell you exactly whats going on with the stalling may be worth the 40 bucks to a mechanic for a static test

Thanks for the advice. Will probably be taking it in to the mechanic.

Take off the flame arrestor and check to see if the muffler is there. If the engine was replaced most likely the muffler was yanked. Its not needed and is purely to keep the whistle/gasping noise down. If your mech can just throw a scanner on he can tell if its the iac. They are pricey and last time I changed one........(last week) it was like 125 bucks. Keep us updated