'88 Mercruiser 5.0L/LX

[stealurface]

Recently when starting the boat and at high rev in N, I am getting a very high pitched "whistleing" noise. It goes away when in gear and running.<br /><br />Any ideas on what I can check?<br /><br />Thanks - CM

 

[Bondo]

Re: '88 Mercruiser 5.0L/LX

Vacuum Leak ???????

 

[stealurface]

Re: '88 Mercruiser 5.0L/LX

Sounds more mechanical - the thing is tip top otherwise.