F115 whining noise

[trapper1014]

Hello I have a 2010 Yamaha f115 txr. Making a noise inforward gear only from 1,000 to 1500 RPMs does not do it in reverse and does not do it on dry land with the muffs on. Checked the oil in the lower unit it's perfect. I greased the drive shaft that goes through the plastic bushing. The only thing I can figure is I changed the prop size I was trying out a new prop size and maybe I put the thrush washer backwards would it make this noise if I did that? Has anybody had this issue before.

 

[Stuatsea]

Possibly the prop is singing when it's happy, goes away under more load? Remedy on our yacht propeller is to square off the trailing edges of prop with a file. Also only occurs on a clean prop. Change the prop and see if it changes. It's a lot more ringing sound on a yacht prop as it echoes through the hull but might sound like that on an OB.?