Prop Blade Damage - Can this damage the engine if used?

[MattB]

I look after the safety boats for a sailing club. One of those boats is about a 4.5 meter rib with a 40hp 2 stroke Yamaha engine from around 2005.

Last weekend I noticed that somebody using the boat must have been in the shallows too much which has resulted in damage to the prop from hitting the lake bed. All three blades are fairly badly dented with one of the blades with a chunk or two missing.

I tested the boat out after the issue was noted and don't think the performance is effected to much but there was a slight vibration through the wheel at speed.

The question is - is this likely to cause wear/damage etc in the engine itself and would the more experienced of you recommend a replacement prop? It is a safety boat afterall.

Thanks

[Nos4r2]

If it's vibrating, get it fixed. It'll goose the gearbox eventually.

[Bigmuz7]

you could argue about extra gearbox wear etc.. but not likely to be an issue of an engine that size .. however most of us like to err on the side of caution, and would get it fixed. Theres a few companies who will do it, but i havent used any in ages, others will give you the latest on whos best.. a pic would be good though so as to see if it is dooable

[kerny]

Crowther Marine - Propeller and Stern Gear Specialist


http://www.steeldevelopments.net/

[Ribochet]

Originally Posted by MattB

The question is - is this likely to cause wear/damage etc in the engine itself and would the more experienced of you recommend a replacement prop? It is a safety boat afterall.

Without a doubt change it

BTW what do you mean by "It is a safety boat after all" in relation to this post.

[AJ.]

Originally Posted by Ribochet

Without a doubt change it

BTW what do you mean by "It is a safety boat after all" in relation to this post.

My thoughts exactly if it is a safety boat so there to pick up people if they go into the drink, surely keeping this boat in tip top condition is a priority. Leaving the prop damaged which could lead to a damaged gearbox and sods law when you need to pick some one up out of the water is not a good place to be.

[Hightower]

As others have stated, get the prop repaired or replaced. The Vibration will put the bearings, drive gear under undue stresses and probably bugger up the seals too which will let water in to the gearbox.

[Downhilldai]

Originally Posted by Hightower

As others have stated, get the prop repaired or replaced. The Vibration will put the bearings, drive gear under undue stresses and probably bugger up the seals too which will let water in to the gearbox.

^^
What he said. Take this advice.

[9D280]

+1

Unless you are compacting a few tons of type 1, a Beach Boys fan or a woman, vibrations are genrally a bad thing.....

[simsy]

Take it off and hammer it carefully to straighten it, it will move very easy if aluminium... then consider a replacement if chunks missing or chasing performance.....

[Ribochet]

Originally Posted by simsy

Take it off and hammer it carefully to straighten it, it will move very easy if aluminium..

[A1an]

For the price of a prop, buy one, a bad/unbalanced prop is only good enough for getting you home.

[Hightower]

Originally Posted by simsy

Take it off and hammer it carefully to straighten it, it will move very easy if aluminium... then consider a replacement if chunks missing or chasing performance.....

I would suggest the above unless it's you're only prop and you needed it for an emergency.

I have had a new looking unblemished prop run out of balance. You'd of never of know just by looking at it, but it was and cost me to get it balanced.

[SPR]

Originally Posted by A1an

For the price of a prop, buy one, a bad/unbalanced prop is only good enough for getting you home.

+1

A new prop - 2 tanks of fuel in cost...

[paddlers]

For the relatively small cost send it to get assessed & repaired. It'll come back looking like a new one ( until next time you run aground).

[MattB]

Thanks for the advice everyone. Will source a new one and put this into storage for emergencies.

Safety boat in this case is to go out with sailing dinghies when they are racing and potentially rescue people in the water if they get into trouble. Boat needs to be ready to go at all times.

Cheers

[kerny]

Originally Posted by MattB

Thanks for the advice everyone. Will source a new one and put this into storage for emergencies.

Safety boat in this case is to go out with sailing dinghies when they are racing and potentially rescue people in the water if they get into trouble. Boat needs to be ready to go at all times.

Cheers

I picked a very bad mangled prop up cheap and took it to Crowthers in Oldham,it came back balanced and like new. £50 l now carry it with me as a spare.

[Ribochet]

Originally Posted by MattB

Safety boat in this case is to go out with sailing dinghies when they are racing and potentially rescue people in the water if they get into trouble. Boat needs to be ready to go at all times.

So imagine the scenario of " you are the coxwain with your crew along with 2 rescued sailor and 20cm of water onboard, its gusting F5 and you are making for the shore against the wind" - would you want a dodgy prop cavitating away?

[simsy]

Yep, small dings can be tapped out of a prop.....

[Ribochet]

Originally Posted by simsy

Yep, small dings can be tapped out of a prop.....

Part of original post

Originally Posted by MattB

All three blades are fairly badly dented with one of the blades with a chunk or two missing.

A bit more than a small ding