Is it a worn cutless bearing ?

Jonathanbell903 said:
Puff (if I can be so bold to call you that)
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Well, most people call me 'Sir'................. but, since we haven't met, you may call me whatever you wish. :D


Let's see what the engineering company comes up with...as well as their bottom line. I don't really like rope-cutters; I think that they are more trouble than they are worth especially when dealing with rope that is not tied to anything. Just my personal opinion.
 
Could be the drive plate on the engine flywheel.
The older ones have springs in the plate which are similar to a clutch plate. Over time, the seating of the springs wears and at low revs you get a Kachunka...Kachunka ...sortof sound. Once the power is on they lock up and are silent. Bothersome but not an urgent issue.
If its more of a Kalunka...kalunka sound , then your'e in trouble!!!!!!
 
Jonathanbell903 said:
Puff (if I can be so bold to call you that) what a great idea !!

I'm looking at the boat on Friday as the marina said they didn't want to put it back in incase there was an issue. But I motored for about 4 miles with the dam thing spinning and had no water ingress just the blasted noise - now the cutter has been removed I don't see that there can be any remaining problems ? Clearly I need to look first but at the moment I have asked an engineering company to quote me to repair but I think they will quote on replacing the fitting attached to the hull that the shaft passes through........ Not sure if the expense is necessary ?
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Presumably the noise has now gone with the cutter and striker removed. The shiny tube in you second picture is the cutless housing. It is a relatively thin bronze casting which is why a clamp on striker plate was used. What I suspect has happened, going back to my comments on your original picture, is that the cutter was incorrectly positioned on the shaft and had seized, so causing the striker plate clamp to turn on the cutless housing. Sort of educated guess without seeing how it was before it was removed. It is possible you may have to replace that housing although unlikely it will have worn enough for that.

As I suggested speak to Robin Shaw at Ambassador - he designed and made your cutter so is the best person to advise on what can be done to refit your cutter.
 
Thanks for the advice Tranona

That is what I think the marina manager was trying to describe to me, I am down there first thing so I can see myself. It's the wear on the bronze casting I am concerned about and how much wear is or isn't acceptable and if there is wear what the repo cushions of that could be.
 
Despite the thin wall the casting is pretty substantial and is only there to hold the cutless in. The clamp you have for the fixed striker is adjustable to cope with variations in diameter and taper. The real issue you have to deal with (assuming you want to refit the cutter) is to check whether you have worn the bearings away and then ensuring when you re-install you do it correctly so that it can cope with the inevitable movement fore and aft as you go in and out of gear.

Make the phone call I suggested 01962 775405
 
The jury is back and ............ The rope cutter was definitely at fault. The pictures show it after the main body has been removed just leaving the blade that rotates (I have as you can see removed this as well so there isn't any cavitation or vibration issues). It seems that the bronze outer selvage is worn due to the rope cutter coming adrift but nothing that I can see will effect the shaft spinning or the prop working. I am not planning on reattaching the rope cutter so for now it all looks ok, there was no water ingress either.

Thank you for all your comments and advice and after seeing these pictures if you have any other comments please let

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Thought so. If it is repairable with new bearings then you need a spacer between the gearbox coupling to move the shaft back 15mm so that you can locate it correctly.
 
Doubt that will do any good. First it would interrupt flow of water into the cutless bearing, second it would have to be loose to deal with fore and aft movement of the shaft and lastly any serious bit of rope or net would smash it to pieces. The type of cutter you have is arguably the most effective and popular and works well if properly installed.
 
Thanks for the update. Glad to hear that there was no serious damage.

If you are going to fit the plastic tube make sure that (1) it is loose, e.g. if the shaft is 25mm use a tube that is 30-32mm bore and (2) there is a clearance of around 5-6mm between it and the cutless bearing when the shaft is pushed well forward. It will NOT impede water flow. The tube should be the thick and rigid type, typically around 4-5mm wall, NOT the thin type that is used for drains. Before the advent of push-on systems (Acorn and similar) we used to cut BSP threads on these pipes for elbows, sockets, angle valves, etc. in installations for water supplies; they are NOT crushed easily!
 
I really doubt any plastic tube would help at all, if the rope is loose and comes off easily it was never going to be a problem, if it winds up between the prop and the bearing carrier there is enough force to pull the gearbox off, that kind of force and the heat involved melt the rope (and any plastic pipe) into a solid lump. Most of our customers are commercial and believe me they have the rope round prop problem far more often than leisure boats. The more Hp the more the damage, yachts can often get away with less damage as they have tiny engines.
 
Personally If that was mine I would get the bonding checked out while the boat is blocked up, looks like there maybe a touch of Galvanic action in that stern tube bearing carrier.
 
Tim D said:
Personally If that was mine I would get the bonding checked out while the boat is blocked up, looks like there maybe a touch of Galvanic action in that stern tube bearing carrier.
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Those marks are where the clamp for the rope cutter has been turning. Doubt the housing is bonded to an anode as generally there is no issue with galvanic action on a bronze housing with a rubber bush inside it.
 
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