Prop problem

[rosta]

Thanks to a bit of over-enthusiastic crewing I've taken a chunk out of one of my props. I'd swear I said "push the stern off when you've untied the bow", instead the bow got untied and then shoved out very hard.

I had just engaged reverse, so the engines were turning very slowly and when the prop hit the rock the engine stalled. Now there's some vibration where there never used to be, when I raised the legs I found a V shaped nick about a centimetre deep in one of the alloy blades. Please reassure me - am I likely to have done any further damage to shaft or bearings?

Also:

- is it possible to replace a prop without taking the boat out of the water?
- how can I find out which prop I need, there seem to be lots of variations? Will there be any markings on the props, they are the alloy ones original fitted by Volvo? If I can ascertain which is the correct one I could combine a lift/clean with a prop replacement.

Can anyone give me some technical advice (and put my mind at rest)?

TIA

 

[mad_boater]

Thanks to a bit of over-enthusiastic crewing I've taken a chunk out of one of my props. I'd swear I said "push the stern off when you've untied the bow", instead the bow got untied and then shoved out very hard.

I had just engaged reverse, so the engines were turning very slowly and when the prop hit the rock the engine stalled. Now there's some vibration where there never used to be, when I raised the legs I found a V shaped nick about a centimetre deep in one of the alloy blades. Please reassure me - am I likely to have done any further damage to shaft or bearings?

Also:

- is it possible to replace a prop without taking the boat out of the water?
- how can I find out which prop I need, there seem to be lots of variations? Will there be any markings on the props, they are the alloy ones original fitted by Volvo? If I can ascertain which is the correct one I could combine a lift/clean with a prop replacement.

Can anyone give me some technical advice (and put my mind at rest)?

TIA

I think you will be very unlucky if you have damaged the shaft and bearings.Any slight damage to the prop will cause vibration.The size of the props are usually stamped on the boss (not the blades) a diver might see the size.It is very difficult to remove the prop while in the water.If you could get the size and don't mind buying a spare you could do the job on a lift and hold basis otherwise its lift and chock while you send the prop away for refurb.
Sorry to be the bearer of ill tidings.Good luck

 

[duncan]

agree it's unlikely you have any more damage - I have mangled a pair of stainless props without damage to the bearing assembly on a Bravo III. POssible but very unlikely in your case.

changing the prop with the boat in the water is a doddle - easiest way is to have the stern towards a pontoon with leg fully raised and get a few friends to sit on the bow; work from pontoon. Use a catch net whilst working in case you drop anything. Alternative is to anchor in very shallow water and work standing up.

the above process will also enable you to see the prop markings.

if you want to effect a temporary bodge the use a hammer on one side and something bigger on the other. If you get the shape back you will probably remove the vibration even if there is still some missing metal.

 

[oldgit]

No and Yes.

Ideally lift legs and get into as shallow water as possible,it is possible to do this standing on swim platform,but better if you get into water,it is easier.
Would not bother about that tiny nick on single blade,doubt that would be detectable in vibration dept,have the other blades been actually bent ?,fix it when you next have boat out of water.
Talk to Steel Developments about mending.If not then Ebay for replacements or with Coastal Rides.

 

[mad_boater]

I think you will be very unlucky if you have damaged the shaft and bearings.Any slight damage to the prop will cause vibration.The size of the props are usually stamped on the boss (not the blades) a diver might see the size.It is very difficult to remove the prop while in the water.If you could get the size and don't mind buying a spare you could do the job on a lift and hold basis otherwise its lift and chock while you send the prop away for refurb.
Sorry to be the bearer of ill tidings.Good luck


I thought when you mentioned shaft and bearings you didn't have legs.Removal of the props will of cource be easy with legs as posted.

 

[tinkicker0]

I think you will be very unlucky if you have damaged the shaft and bearings.Any slight damage to the prop will cause vibration.The size of the props are usually stamped on the boss (not the blades) a diver might see the size.It is very difficult to remove the prop while in the water.If you could get the size and don't mind buying a spare you could do the job on a lift and hold basis otherwise its lift and chock while you send the prop away for refurb.
Sorry to be the bearer of ill tidings.Good luck


I thought when you mentioned shaft and bearings you didn't have legs.Removal of the props will of cource be easy with legs as posted.

That's how I interpreted the post too. I Visualised shafts, brackets and cutlass bearings.

If on legs, can't speak for VP cos I have no experience of them, if Mercruiser, remember to replace the prop rubber bushes as a matter of course, which will have taken the hit instead of the leg internals.

It is helpful to supply the make and model of leg / boat/ engine when posting enquiries such as these