Prop blade out of true

[Triton II]

My Yam 2003 FT60 13.5 x 15 original prop has one blade that is about 1mm out of true. The boat goes well, the motor doesn't vibrate and there is no physical damage to the blades... I just noticed this problem today while cleaning the prop. Is it a problem that needs fixing?

 

[Triton II]

Re: Prop blade out of true

No replies so maybe I should elaborate. A Yam service guy told me that the shaft seal would get torn apart by the out of true prop - yet there is no vibration and the top speed of the boat (on GPS) is exactly the same, the trolling speed is unaffected and the tip of the blade is approx 1mm out of true. Surely such a small bend in the blade cannot "tear apart the shaft seal, stress the shaft and eventually ruin the lower leg" which is what I'm being told. If that is true then the majority of boats in my area must have cut up seals and there are many, many props out there is far worse condition than this one which is like new apart from the slightly bent tip. Any ideas rodbolt?

 

[Dunaruna]

Re: Prop blade out of true

Mark, is it alloy or SS?<br /><br />1mm will not cause any problems. To put it into perspective, 1mm = 39 thou. The average spark plug gap.<br /><br />Aldo

 

[jafa]

Re: Prop blade out of true

If it took a whack you could take it to a local prop shop. They will put it on a bench and "adjust" it back into shape for a lot less than the cost of a new one. It should all be square when you get it back. That said it may be that its still in balance. Remember you add weights to a car wheel to make it spin evenly. Even straight from the factory it may be "bent" but still spin evenly.

 

[Triton II]

Re: Prop blade out of true

Thanks guys, you’ve put my mind at rest. It’s an alloy prop Aldo. We’ve got a prop shop called Austral propellers down the road at Peakhurst so I’ve booked it in to check the balance and if necessary, straighten the ‘bent’ blade. They’ll give it a flash coat of white to bring the old girl back to her original pristine state before I flogged her for 280 hours.

 

[rodbolt]

Re: Prop blade out of true

yep<br /> a blade that is .039" or 1mm out wont cause a noticable vibration at the helm. the prop shaft bearings may notice it though. the seals wont care until or unless the bearings fail. part of the montly maint is to inspect the prop. thats the time to catch things

 

[Triton II]

Re: Prop blade out of true

Thanks for the info rodbolt. Glad I took it in. I've just been told it's straightened out fine and doesn't need balancing so I'm happy.