1972 mercury 140hp

buzzm19

Petty Officer 2nd Class
Joined
Dec 14, 2009
Messages
152
Hi guys, I need some help on my 1972 140hp mercury, it makes a weird noise I can't figure out. I have tried to upload the video to no success. If you guys would go to youtube under (Buzz's glastron) you will see the video of the motor making the noise. Thank you and any help would be well appreciated. Thanks Buz
 

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
27,033
Re: 1972 mercury 140hp

A bit tough to tell cause of the wind noise. If the noise was a rattle, check the distributor pully cover for tightness. if it was a rumble, check the gear oil. Run it w/o the cover if the noise is in the powerhead and see if you can isolate it.
 

aussieflash

Lieutenant Junior Grade
Joined
Feb 5, 2011
Messages
1,004
Re: 1972 mercury 140hp

Check compression and inspect plugs for metal shavings etc.That noise seem to stop half way through when guy came into shot.Was something else rattling and making that noise?
 
M

Maxz695

Guest
Re: 1972 mercury 140hp

Check your Mounts and mount bushings. sounds like the brackets are ratteling. The cut out in the begining I supose was you throttling
 

buzzm19

Petty Officer 2nd Class
Joined
Dec 14, 2009
Messages
152
Re: 1972 mercury 140hp

Guys, I am going to fire it tonight and check for vibration and I 'll let you know what I find. Thanks Buz
 

buzzm19

Petty Officer 2nd Class
Joined
Dec 14, 2009
Messages
152
Re: 1972 mercury 140hp

Guys, I am going to look at it tonight, so far the plugs look good and no metal filings. Thanks Buz
 

emoney

Commander
Joined
Jul 19, 2010
Messages
2,551
Re: 1972 mercury 140hp

Did a '72 Merc come with an overheat buzzer, and if so, are you sure that's not the sound? Those buzzer alarms can sound rather squeeky when they get old.
 

buzzm19

Petty Officer 2nd Class
Joined
Dec 14, 2009
Messages
152
Re: 1972 mercury 140hp

Well Guys, I checked for any loose parts, definatly not an alarm (I don't have one). The only thing I found so far and I did it for the prop being closer to the gear box, I do see rub marks on the retainer ring that holds the bearing carrier in place (I know there's a name for it I just can't remember now) I was wondering if it could work its way up into the motor leading to a false diagnosis, I'm sure someone has left the spacer out by mistake, anyway I won't know till I put in the water. The noise only happens under load, which could be as the prop is pushing back putting a load on the prop shaft. I will let you guys know what happens. Thanks Buz
 

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
27,033
Re: 1972 mercury 140hp

Buzz, You are supposed to have a heavy metal thrust washer that keeps the prop in the proper place. Without it the prop will destroy the gearcase,
 

emoney

Commander
Joined
Jul 19, 2010
Messages
2,551
Re: 1972 mercury 140hp

I agree with an earlier poster who mentioned the noise quit with the passenger came into view of the camera. Seems like when the ballast (i.e. 'him') shifted, the noise stopped. I'd try to do my diagnosis with 2 passengers; one to operate the helm the other to act as the ballast, and myself listening for the source. That noise could be the speedometer pitot taking in air because it's mounted too high on the transom and when your passenger moved to the stern, the boat sat down in the water deeper eliminating the noise.
 

merc850

Commander
Joined
Jul 7, 2010
Messages
2,020
Re: 1972 mercury 140hp

Lower-Units0061.jpgBefore you do any more damage make sure that the rear thrust hub (Nr. 25) is installed and there is no fore and aft movement in the prop.
 
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