2000 21V whistling noise at certain rpms...suggestions?

[tmilldw02]

Recently purchased a 2000 tige 21V (with scorpion engine) and it has a significant whistling noise from the engine that occurs only at certain rpms. A slight adjustment of the throttle makes it go away. Didn't think it was such a big deal but it drives my wife crazy. I found an old thread with a similar complaint on the exact same boat, but there was no consensus as the cause or how to correct it. Any thoughts?

[laserfish]

Check for vacuum leaks.

[Moki]

Unfortunately, it is normal to make that sound.

[mdk681]

I have been told by multiple people that it is normal. I think it might be something to do with the throttle body opening and closing? Not exactly sure, but my 21v does it whenever I am pulling a wakeboarder or up on plane...

[boatwakes]

It is the Idle Air Control valve (IAC) opening and closing at throttle up and throttle down rpm (off idle). Normal but it wouldn't hurt to pull your flame arrester (air cleaner) and wash with simple green, air dry and reinstall. They pick up a descent amount of scum over the years and can contribute to your motor whistling dixie or other tunes depending on your personal taste.

[techjmw]

I just bought a 2100v 2001 and it does this exact same thing. Glad to hear it isn't abnormal. I will pull off the cleaner also and see if it is dirty.

[Z1Fan]

I would also call mercury and ask if the have a different gasket for between the throttle body and intake manifold , I have a similar issue with my PCM , and they were aware of the issue and designed a slightly different gasket which changed the air flow and the whistling stopped

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[cclarke89]

Its your flame arrester. Its like when you take plastic and pull it tight then blow on it, it will make a whistling noise. I took mine off to see if it was that an it went away. I just deal with it the noise now..