Yamaha 150 4 stroke prop chatter

[cruiser54]

Hi,
First post!
I have a 2010 F150 4 stroke with 35 hours usage.
I have what I think it is called prop chatter.
Motor runs perfectly, however when I start it up and select reverse to back off trailer there is a metallic rattling noise coming from the motor that disappears when revs go above about 750 rpm.
When going slow in forward gear the motor is whisper quiet but when revs drop below about 750 rpm this metallic rattle appears.
In summing the situation up when ever in reverse or forward I get a metallic rattling noise coming from my motor when travelling below 750 prm.

On investigation this noise is rather common with F150s.
I understand that the noise is not harmful but it is annoying and I really want to get rid of it. I also understand that changing the prop may remedy the problem. *I am running a standard Yamaha 17 inch black SS prop.

Can anyone please advise a fix.

Thanks.

[boats.net]

Prop chatter will not harm anything. Using an aluminum prop is about the only way to eleminate chatter, Yamaha Reliance Series SS props does work very well and does help with chatter.

[cruiser54]

Thanks for the advice.
Problem fixed.
On investigation dealer supplied the wrong diametre prop, 15 x 17 T series?
This also contributed to rather poor performace issues.
Replaced this prop with a 13 3/4 x 17 black SS M series which has imporoved performance greatly but most of all eliminated the prop chatter - proving the point that F150s do not have a liking to large heavy props.
Cheers,