High pitched whistle

[dozerII]

On my 1972 Mercruiser 120 I get a high pitched whistle after the engine warms up. I just finnished a carb rebuild and thought this would take care of it, but not a chance ( needed it any way). The engine runs great even after the whistle starts. I took a length of fuel hose and jammed one end in my ear and used the other to search for the whistle, I found it on the intake gasket on the first two runners, as shown in the photo. While it was running I sprayed the area with a spray lube and the whistle stopped and would not come back. Is this something to worry about, or does it need immediate attention?
Thanks Glen

 

[[OBC]Patch]

Re: High pitched whistle

Try some high temp silicone, or its coming off for a new gasket.

 

[Alpheus]

Re: High pitched whistle

YES it needs immediate attention. That is a major vacuum leak and will cause a lean condition in your engine and harm vital parts. DO NOT skimp on this problem with silicone or temporary fixes. You dont want to suck anything in there do you? Take the intake off and put a new gasket in there. You did the hard part by finding the problem, now just fix it, and fix it right.

But as always, thats just my opinion...

 

[Bt Doctur]

Re: High pitched whistle

Be a good idea to replace the rubber line with some steel brake line tubing cut and double flared to size.

 

[dozerII]

Re: High pitched whistle

The problem is I know the motor is a 120 but there is no serial number tag on it and I don't know what gasket set to order. I don't think the motor is origional as there is no tag and on the starboard side under the oil sending unit it says made in Mexico, there is a number 770 and an another one that is almost impossible to read, how do I find out what gasket set to order.
Thanks Glen

 

[Alpheus]

Re: High pitched whistle

http://www.mercruiserparts.com/Show...r=1559&bnbr=130&bdesc=GASKETS+AND+GASKET+SETS

 

[a70eliminator]

Re: High pitched whistle

On my 1972 Mercruiser 120 I get a high pitched whistle after the engine warms up. I just finnished a carb rebuild and thought this would take care of it, but not a chance ( needed it any way). The engine runs great even after the whistle starts. I took a length of fuel hose and jammed one end in my ear and used the other to search for the whistle, I found it on the intake gasket on the first two runners, as shown in the photo. While it was running I sprayed the area with a spray lube and the whistle stopped and would not come back. Is this something to worry about, or does it need immediate attention?
Thanks Glen

Have a look at the spark plugs, the one opposed to that intake runner especially, compare it to the others, from what you say the intake is leaking and the plug should confirm it.

 

[dozerII]

Re: High pitched whistle

Thanks for the help, I just changed the spark plugs but the old one all looked tha identical nice brown color.
Glen