noise in sterndrive

[seulb]

I have a 1971 120hp sterndrive that when I let off the throttle make a ratchiting noise. I haven't replaced the gimbal bearing but am planing on replacing it this spring. What could cause this noise? Thanks

 

[Bondo]

Re: noise in sterndrive

Ayuh,... Donno...

It could be as simple as the motor slowing down quicker than the boat....

The clutchdogs in the drive will ratch if the motor isn't turning as fast as the prop....

 

[chiefalen]

Re: noise in sterndrive

What make is this ?

 

[seulb]

Re: noise in sterndrive

The sterndrive is a Mercreiser and it's in a 1971 larson tri-hull

 

[chiefalen]

Re: noise in sterndrive

Thats pre alpha right ?

When was the u-joints and gimbal bearing even looked at last ?

 

[KJSmitty]

Re: noise in sterndrive

Ayuh,... Donno...

It could be as simple as the motor slowing down quicker than the boat....

The clutchdogs in the drive will ratch if the motor isn't turning as fast as the prop....

Yep,
I remember our first boat, early 70 vintage with a 120HP Merc I/O as well. Every once and a while it would dye if you pulled the throttle back quickly after a skier fell etc.. I had no idea what a "clutchdog" was back then yet it definitely made the "ratchet noise" while the boat coasted to a stop.

Not saying that is definitively the OP's issue, but very likely etc..

Cheers

 

[seulb]

Re: noise in sterndrive

I don't know when the gimble bearing or U-joint had been looked at last I just bought the boat last June. But have no fear it won't go back in the water untill I inspect them this spring. I was just hopeing that I didn't have something in the lower unit going out. But from what I'm reading on the forum with everyones help is that it probably is the clutch dog.

 

[Don S]

Re: noise in sterndrive

The gimbal bearing or ujoints are not going to make a ratcheting noise. Next time you run it, when you pull the throttle back, go to neutral at the same time and see if it still does it. Of, when it starts to ratchet, go to neutral and see if it stops ratcheting.