“Singing” prop

• Sep 7, 2020

• #1

Pony Racer

Member

Aug 13, 2015

167

Ct

Boat Info

2005 Sea Ray 390 Sundancer

Engines

Twin 8.1 S-HO 496's, v-drives

Just had my props refinished and reinstalled. They look great. Pitch was not changed, props were only cleaned up and rebalanced.
Now I have a harmonic resonance (sounds like a tuning fork) between 800-1200 rpms. this a problem with the port prop only was it not installed properly or is there an issue with the prop.
Never had this issue prior.

 

• Sep 7, 2020

• #2

ocgrant

Official Bahamas Boating Ambassador

GOLD Sponsor

Dec 31, 2006

2,819

Miami / Ft Lauderdale

Boat Info

H2O Therapy
2006 Sundancer 48
Novurania 430DL
HighField 340-FCT
Yamaha EX-R
Raymarine
PADI DM

Engines

Cummins QSC 540's

Sounds like you are onto the issue. I would pop it off and re-install it. Make sure the keyway is all good and snug.

 

• Sep 7, 2020

• #3

Jeremygavin

Well-Known Member

Mar 6, 2012

2,054

Cape Cod, MA

Boat Info

2011 520 Sedan Bridge
2016 Sea Ray 19 SPX OB
2019 Walker Bay Generation 340

Engines

Cummins QSM11s
Mercury 150 Fourstroke
Honda 40hp

Sounds like prop sing to me. I had a prop sing issue when I bought my boat. Took the prop shop 2 tries to tune it out of the prop. Your prop guy will be aware of it and can put anti-sing edges on the prop. Have it removed and get it back to them to put the Anti-sing edges on it. In the meantime no damage is done running it the way it is. I put 120hrs on mine last season with a sing issue no problem.

 

• Sep 7, 2020

• #4

sbw1

Well-Known Member

Oct 10, 2006

8,185

West Michigan

Boat Info

This is listed in my signature

Engines

This is listed in my signature

Trailing edges of props should be flat. Fix is to file the offending to the proper orientation by a person who understands the issue. Not a serious problem and is easily fixed. You might also want to check the alignment of the transmission to the engine for the offending side. That may play a role.