Lost portside propeller on California 34

Hello friends!
I am the new owner to this boat. And a new mariner to power boat.
Me and my friend just own a 1979' California 34, with twin Perkins engine 6.354T
Last week, on the way back from a cruise. the port side propeller fall off. we end up with one engine back to our slip. I have dive down and got the starboard side propeller size measurement. I am trying to find a right size propeller to put on, get she back to the water. I have very limited knowledge on this. Could some one give me some suggestion about this problem? Thanks a lot.

Best,

Hoche

You need the shaft size as well as the prop size. The prop size is usually stamped on the hub and you could measure the shaft with calipers but probably better to have the boat out of the water and take the prop to a prop shop for a good match. A properly installed prop doesn't just fall off. Doing it right in the water is possible but.....

If this boat is new to you, did you get a survey? Have you gone over it’s systems? Did the wheel fall off due to corrosion or did someone fail to put in a cotter pin? This doesn’t just happen, you need to figure out why and look closely as to whether this boat is dangerous... to you and to those who will risk their lives to save you. That’s the best I can do with no more information.

So did nuts back off or shaft fracture?

You can measure shaft inside the boat, if standard SAE shaft, taper fit prop will also be standard.

If you dropped the prop in the marina, sometimes divers are good at finding them.

You want to take off your remaining prop and have it matched to any new one you procure.

Best advice, take it to a yard for a short haul. You can inspect the shaft, the threads, and read to specs on the other prop. Also, you have the opportunity to check the hull for damage too. OR you can research the net for the information.
Gotta love the net for obscure information.

My guess is when you bought the boat it was not surveyed, or the surveyor was very incompetent. Like others have said, they don't just fall off. There are two large nuts that are tightened together so they wont back off and then there is a large cotter pin just in case something goes wrong. A surveyor surely would have seen it was missing. Also, if it came off while under way there could very well be some hull damage. Pull the boat out and check things out.

This boat is new to me, we did a survey couple month ago in May. but... on the report it said everything is good
I have dived down, the nuts come off the shaft, the shaft looks OK. the end of shaft is tapered, 1-1/8 to 1-3/8, the diameter of the propeller is 20 inch. There is one thing is ware to me, on the other shaft, there is no look pin, only have two nuts tightened together. Due to the shaft vibration when the propeller fall off, the shaft through hull seal leaking water in to the bilge.

The propeller is come off about about the entrance of the harbor. Is it possible finding them. I have dived in the marina, the visibility is very bad, the bottom is mud and soft

One other suggestion. The replacement prop will probably need to be fitted to the shaft. This is done by applying Prussian blue ( a dye used in metal work) and a lapping compound ( commonly was used in days gone by to lap valves in engines). Not sure if there is a way now days for a diver to do this under water.
The surface of the propeller hub must make complete contact with the drive shaft.

If you have a good idea of the area the prop fell off then it MAY be worthwhile hiring a diver for an hour or two's looking. for a fee of $300-#400. [total guesstimate]

I don't know what you have for props and it doesn't really matter here but a new prop will likely be several thousands of dollars plus all the other nonesense of matching it.
If you find it you will be money ahead. If not then the cost will have be eaten as a boat expense.

Get the boat pulled. As said these things do not just fall off. Someone didn't do their job properly. Double nuts and a cotter pin should have ensured it stayed put.

I will mention that if the prop had been properly fitted it likely would not have come off even if the cotter pin and the nuts fell off.

Get the other prop checked that it is fitted properly AND the nut and cotter pin are setup correctly. If that is not checked you could be on the verge of losing the other.

Directions have been given above for proper fitting of the shaft/propeller so read it carefully and be sure it is done properly. If you don't understand then ASK again. You can be directed to an experts way of doing this, with photos, that can be downloaded: Tony Athens of Seaboard Marine who offers a huge amount of info for free and this is one of those guides.

Another reason for pulling the boat and doing an inspection is the prop may have damaged the hull when it went. They do not always go down immediately without first smacking the hull, cutting it. I knew two people that happened to. They lost a prop, one lost a blade first, and the hull was damaged.

It might be worth getting the insurance company involved. You might end up paying for it all but maybe not. If there is further damage it may be more than thought to get repairs done properly and if you start messing with it without contacting them you may end up eating it all.

There are divers out there that have metal detectors, specialize in basically looking for of all things, guns. If they can find a gun in a lake, they probably can find the prop.

If you know the shaft size (1 3/8 or 1 1/2) and you know the diameter, (20") then you can contact any prop shop and they will give you recommended pitch. They will want to know length of boat, hp of engines, max rpm of engines, desired top speed ,etc.

For example, they may recommend 20X9 props. You can then shop around for a used set at substantial savings. You might find a 20X10 set. This would work but would lower your top rpm a bit. You can find a lot of information online about the relationship between diameter and pitch.

You should be able to take some scotch brite to the hub of your remaining propeller and find the manufacturers size marking. You might get lucky and find a used LH prop. I would also check to see if the end of your shafts have drilled holes for cotter pins. If not, I would add them.

Pull the boat. Any competent yard should be able to tell you what prop is still on there. You want to inspect the shaft for runout and damage.
Nuts coming undone? Something is fishy.

Was the engine in reverse when the prop came off?

If you haul the boat you can then inspect everything. Hire a shipwright to remove the remaining prop. Get it inspected and matched to a replacement. There are shops than can sell you a used reconditioned prop. I did that a few years ago when I destroyed mine when it hauled up a crab pot. It was “pink” anyway. I paid around 600 for a nice Nibral Michigan unit. I don’t know any shops in your area, but plenty here do I’m sure.

Good luck

Haul out, check both shafts. Good time to change zincs.

dhmeissner said:

If you haul the boat you can then inspect everything. Hire a shipwright to remove the remaining prop. Get it inspected and matched to a replacement. There are shops than can sell you a used reconditioned prop. I did that a few years ago when I destroyed mine when it hauled up a crab pot. It was “pink” anyway. I paid around 600 for a nice Nibral Michigan unit. I don’t know any shops in your area, but plenty here do I’m sure.

Good luck

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+1!!!!!!! Great advice! Be sure to match the props before reinstalling them.

Call your insurance company to see if this is covered under your policy. You might be in luck.

Do you have a chart plotter ? If you can go back and look at your route there will be a course and speed change when the prop came off. Then you'll have the exact GPS coordinates of where to start looking.