I have a 2005 496 Mag bravo 3 and get this air whistle noise, I cleaned the fire arest. filter still have noise. It seems to be the most noticable when running at low rpm and coming off WOT any suggestions on what to do????? Would a different air filter solve the whistle??????

My 496 mag whistles also. But it comes from the belt.

hey pol98 I checked the tension and it appears ok, the belt only has 35 hours on it. Did you solve your noise.

I think if you do a search on this in this forum you'll find that a number of people experience this with their 496's. I sure did. I seem to recall that Merc came out with a foam filter(?) of some sort to help out with the issue.

Pat

My 496HO did the same thing, so I replaced it with a K&N arresor/filter. There is a foam piece that goes in the throttle body, but mine had it, and that wasn't the source of my problem. I think that some of the arrestors come with the screeen arranged just the wrong way, and the whistling comes from the air flowing through it, because before I replaced my arrestor, I borrowed another stock one from a friends boat, and the whistling went away. Oh, and the sound was just like a slipping belt.

I have twins and I have the same noise. I had the stock arrestor on an it was very loud. I changed to the K&N Arrestor and the sounds was a little less.
I notice it at about 1500-3500 RPM's and when comming off of wide open throttle. I have noticed that just about all of these motors do it. It has to do with the air flowing through the arrestor into the throttle body.

Or could be the belt.

My 496 whistles too. I wonder what it could be...

hey betitbig is *****whippled or whistles. and I would bet it big if it did whistle it would have teeth.......

What you guys are hearing is the air passing by the throttle body blade. As the blade closes the gap between the housing & the blade gets smaller, making a whissle.
Cobalt drills a hole in the blade & it makes the noise less. I have no info on how big the hole is. I've seen it & I don't like it. I have heard it & I don't see what the big deal is.

Jason it isn't a big deal, but when you spend 100k for a rig one strives for perfection, and when a person steps on board your boat and ask you "whats that sound" makes one try to resolve it, and thats what forums are forum, to help each other bro.....I am finding out that good marine mechanics are hard to find just like auto mechanics, if you want it done right do it yourself.......