Edited: Many thanks for the help

[Kenomac]

Dockhead,

You need to put on the scuba gear, a 7mm wetsuit or drysuit and take a first hand look at your prop and shaft. I’m doing the same thing today in order to clean our prop and underside here in northern Maine, so it’s not like I’m suggesting something I wouldn’t do myself. You most likely just have a piece of rope stuck on the prop shaft which is an easy fix or a loose anode that needs to be tightened.

[kipwrite]

An alternate theory:
A few years back I had a similar experience on a ‘52 Alden, and after much diagnostic work it turned out to be a worn thrust bearing.
Good luck.

[sailorboy1]

Interesting how people are so anxious to be the fix winner they don't read the thread.

I look forward to a closure post and want he finds out when it's over.

[Suijin]

I’ve been on a boat as it’s auto prop slung a blade. The result is a lot more that a tapping. It’s not that.

I’m with atoll on his diagnosis but I’m not sure I would continue without certainty, definitely not into ice.

[a64pilot]

Originally Posted by Suijin

I’ve been on a boat as it’s auto prop slung a blade. The result is a lot more that a tapping. It’s not that.

I’m with atoll on his diagnosis but I’m not sure I would continue without certainty, definitely not into ice.

I don't think anyone said it slung a blade? I was thinking a loose blade, I Didn't think rope cutter as I don't have one.

However a loose blade should be more of a clunk or knock at each revolution, not a tick

[a64pilot]

If they are not proficient diving, Id advise against it, especially in open water.
first in cold water there is a natural gasp reflex that has drowned many a person, and then under a boat in even seemingly begin conditions the motion of the boat can be dangerous.
thirdly, even in shallow water, you need to be able to inflate your dry suit just a little late to prevent the squeeze it's going to do, then if you haven't Dove in it, you don't have the amount of weight to become closer to neutral, and that means a lot of experimenting in cold, open water.

If it's a rope cutter, best to leave sleeping dogs lie.

[Triumphant]

I had the same rope cutter which produced the same symptoms and eventual the annoying bit fell off and voila no more noise

[a64pilot]

Oh, and another thing I Just remembered, cause I don't not dive in ice.
There are special regulators required for cold water diving and or some better regs can have a cold water kit installed, apparently without the special bits, a reg can freeze up and stop working, and an inexperienced, or experienced for that that matter diver does not need that

[malbert73]

+1 for rope cutter. I had same I think

[Seaworthy Lass]

Thanks again for all the suggestions.

Every post is being relayed.

SWL

[Snowpetrel]

Originally Posted by a64pilot

Oh, and another thing I Just remembered, cause I don't not dive in ice.
There are special regulators required for cold water diving and or some better regs can have a cold water kit installed, apparently without the special bits, a reg can freeze up and stop working, and an inexperienced, or experienced for that that matter diver does not need that

I spent an hour or so diving to bolt the heel fitting back on to the skeg in Antarctica. It worked ok. I used a kayaking dry suit with a few layers of polarfleece underneith. Neoprene gloves and most importantly a 7mm wetsuit hoodie. We kept the bottle on deck and I just took the regulator down on a long airhose.

It took a while to get the bouyancy right. And I needed few small weights around my feet to stop my legs floating up. Lots of air needed to be bled from the drysuit out the neck seal.

I had a big bucket of warm salt water on the swim step to warm up my hands and face. No issues with the regulator freezing, but I only worked in about 5 minute blocks. I didn't get cold, and had only slight leakage through the kayaking dryseal zip. For safety I had a harness and spectra line back to the boat plus a lookout for leopard seals. In your case only walrusses come to mind as an issue.

The key thing was the hoodie. I snorkled on tge rudder a few weeks later (we had borrowed the dive gear, and returned it) and I had no hoodie. A thick woolen balaclava just didnt work. Instant ice cream headache...

Hopefully a camera can be used, and diving won't be needed.

[kmacdonald]

It could be the damper plate. That's where the reduction gear spline slides into. It's mounted on the flywheel. It's a long shot but if the other suggestions don't pan out something else to look for.

[El Pinguino]

Originally Posted by Snowpetrel

...............

The key thing was the hoodie. I snorkled on tge rudder a few weeks later (we had borrowed the dive gear, and returned it) and I had no hoodie. A thick woolen balaclava just didnt work. Instant ice cream headache...

Hopefully a camera can be used, and diving won't be needed.

Agree re the hoodie..... it can be worse than an icecream headache...... stuck my head under water for less than a minute a few months back without one.... can cause serious disorientation due to effect on ears....


That said.... coldest I have dived in is 8*C ... 8mm semi dry..... getting the weight right in that first 2 metres is pretty tricky......

[Kenomac]

Originally Posted by sailorboy1

Interesting how people are so anxious to be the fix winner they don't read the thread.

I look forward to a closure post and want he finds out when it's over.

The thread title reads “Urgent Help Needed,” not.... Urgent Criticism of those Trying to Help Needed.

[Snowpetrel]

Originally Posted by kmacdonald

It could be the damper plate. That's where the reduction gear spline slides into. It's mounted on the flywheel. It's a long shot but if the other suggestions don't pan out something else to look for.

Good thought, but if it's doing it under sail with the engine in neutral it can't be the damper plate.