Select to expand quoteJode5 said..
Hi Dexport,
A lot folding props will auto rotate and not close if you just come back to neutral including my Flexofold 3 blade. To stop this the prop needs to be bought to the stoped position even if only momentary. Most people achieve this by selecting reverse after shutdown which is fine if you have a mechanical gearbox that uses engine compression to lock the shaft.
In my case I have a hydraulic gearbox which will not lock the shaft when the motor is not running. For me to stop my shaft auto rotating I need to have the boat going forward with a bit of pace then put the boat in reverse and shutdown while in reverse. Buy doing this the prop must come to a stand still at some point before it starts to try and auto rotate as you are still traveling in a forward direction (complicated)
You can usually tell if the prop is open as you will feel it on the rudder and generally hear and feel a rumble unless it is really light air and in that case you can use the same method as I have to use.
Thanks for that.
After installation and your sailing again make an underwater video. Either use a camera on a "stick" or get in the water with a vane towed so that your abeam the prop while the boats traveling at a couple of knots. Would make an interesting Youtube video and answer a lot of questions.
Select to expand quoteRamona said..
After installation and your sailing again make an underwater video. Either use a camera on a "stick" or get in the water with a vane towed so that your abeam the prop while the boats traveling at a couple of knots. Would make an interesting Youtube video and answer a lot of questions.
Yes Ramona. I plan on doing that. I'll wait till I'm up in some clear water on a reef somewhere. I plan on shifting between gears and filming how the blades move.
Offshore today sailing with a good breeze and sitting at hull speed I went below to see if my shaft was rotating. I have a two bladed folder that is not geared so the blades fold independently. As I suspected the shaft was not even close to rotating. Week before last I was under the boat cleaning the prop. Light finger pressure was all that's needed to fold the blades, they might even fold in the strong current in the river. Turning the shaft with the propeller blades probably took 10 times the effort that folding took so I would say the blades will fold long before the shaft would ever rotate.
Perhaps we should do a survey. People with folding props check whether their shaft actually rotates while sailing!
Two blade folding. My prop shaft usually rotates (but not always) unless stuck in gear. But will fold easily if ghosting into the mooring in neutral. So probably still rotates the shaft even when folded?
I have a 3 blade geared Volvo prop with my sail drive it definitely turns (can hear it) unless in gear.
Interesting. I'm hauling the boat on the 21st to mount the new prop, anti foul etc. will run tests once back in the water.
MB has a Gori folding two blade prop. It usually stops rotating when the engine is shut down but sometimes not. A brief move into reverse and it stops and stays stopped even when back in neutral.
I don't like leaving it in neutral as I sometimes forget and start it in gear.
3 blade folder here . sometimes will rotate after stopping engine but a quick smack into and out of gear will stop it .
A little different on my side,,,3 blade autostream that feathers,
In my case, the resistance/effort needed to feather the prop is more than what it takes to rotate the shaft, so to feather the prop, the propshaft needs to be stopped or rotation needs a level of resistance for the feathering to occur.
I achieve feathering by grabbing the spinning propshaft with my hand or selecting reverse with the motor off.
Due to the design of the yanmar gearbox, the prop shaft will free spin in forward gear when the motor is off (like its in neutral),, caused by the windmilling prop driving the gearbox and NOT the engine driving the gear box. Yanmar warns against leaving the prop windmilling whilst the engine is off with forward gear selected as it causes unnecessary wear and damage to the gearbox.
Select to expand quoteJolene said..
A little different on my side,,,3 blade autostream that feathers,
In my case, the resistance/effort needed to feather the prop is more than what it takes to rotate the shaft, so to feather the prop, the propshaft needs to be stopped or rotation needs a level of resistance for the feathering to occur.
I achieve feathering by grabbing the spinning propshaft with my hand or selecting reverse with the motor off.
Due to the design of the yanmar gearbox, the prop shaft will free spin in forward gear when the motor is off (like its in neutral),, caused by the windmilling prop driving the gearbox and NOT the engine driving the gear box. Yanmar warns against leaving the prop windmilling whilst the engine is off with forward gear selected as it causes unnecessary wear and damage to the gearbox.
Yanmar issued a bulletin that changed the story 180 degrees. Now they say leave the box in neutral. There has been a fair bit on Cruisersforum.com about this over the last few months.
Select to expand quotetwodogs1969 said..
I have a 3 blade geared Volvo prop with my sail drive it definitely turns (can hear it) unless in gear.
These blades seem to have a bit of the tips still exposed to the water flow when folded but I'm surprised there is enough to cause them to rotate. The saildrive shaft is very short so there would not be as much drag as a normal shaft. Gori type two bladers fold into a very streamlined shape with just a blunt hub exposed to the water flow and it takes several pounds of pressure to rotate the shaft by hand.
Select to expand quoteJolene said..
A little different on my side,,,3 blade autostream that feathers,
In my case, the resistance/effort needed to feather the prop is more than what it takes to rotate the shaft, so to feather the prop, the propshaft needs to be stopped or rotation needs a level of resistance for the feathering to occur.
I achieve feathering by grabbing the spinning propshaft with my hand or selecting reverse with the motor off.
Due to the design of the yanmar gearbox, the prop shaft will free spin in forward gear when the motor is off (like its in neutral),, caused by the windmilling prop driving the gearbox and NOT the engine driving the gear box. Yanmar warns against leaving the prop windmilling whilst the engine is off with forward gear selected as it causes unnecessary wear and damage to the gearbox.
I've got the 3 blade autostream too but seems to feather (and stay feathered) as long as I stop it per the destructions. It's a different process to what I'd used before with other boats and of course different boats different results. I've got a pdf of the manual somewhere if you want.
Select to expand quoteRamona said..Jolene said..
A little different on my side,,,3 blade autostream that feathers,
In my case, the resistance/effort needed to feather the prop is more than what it takes to rotate the shaft, so to feather the prop, the propshaft needs to be stopped or rotation needs a level of resistance for the feathering to occur.
I achieve feathering by grabbing the spinning propshaft with my hand or selecting reverse with the motor off.
Due to the design of the yanmar gearbox, the prop shaft will free spin in forward gear when the motor is off (like its in neutral),, caused by the windmilling prop driving the gearbox and NOT the engine driving the gear box. Yanmar warns against leaving the prop windmilling whilst the engine is off with forward gear selected as it causes unnecessary wear and damage to the gearbox.
Yanmar issued a bulletin that changed the story 180 degrees. Now they say leave the box in neutral. There has been a fair bit on Cruisersforum.com about this over the last few months.
That's correct, I always leave in neutral, But when employing a feathering or folding prop , it doesn't matter what gear you leave the drive in once you have feathered the prop because the shaft will no longer be spinning. Like I mentioned , its the free wheeling prop spinning a shaft whilst the engine is off and forward gear is selected that causes damage.
I don't recall Yanmar doing a 180?, as far as I know they have always stated the correct info. The problem has always been yanmar owners not understanding that selecting forward gear will not stop shaft rotation and that this type of rotation is a clutch mechanism slipping rather than a true neutral .
Select to expand quoteSerenite said..Jolene said..
A little different on my side,,,3 blade autostream that feathers,
In my case, the resistance/effort needed to feather the prop is more than what it takes to rotate the shaft, so to feather the prop, the propshaft needs to be stopped or rotation needs a level of resistance for the feathering to occur.
I achieve feathering by grabbing the spinning propshaft with my hand or selecting reverse with the motor off.
Due to the design of the yanmar gearbox, the prop shaft will free spin in forward gear when the motor is off (like its in neutral),, caused by the windmilling prop driving the gearbox and NOT the engine driving the gear box. Yanmar warns against leaving the prop windmilling whilst the engine is off with forward gear selected as it causes unnecessary wear and damage to the gearbox.
I've got the 3 blade autostream too but seems to feather (and stay feathered) as long as I stop it per the destructions. It's a different process to what I'd used before with other boats and of course different boats different results. I've got a pdf of the manual somewhere if you want.
Thanks Serenite, I do have the instructions. My prop feathers simply following the instructions too.
I have easy access to the prop shaft so I always check it after engine shut down,, often I just stop it with my hand rather than clunk the gears.
Select to expand quoteJolene said..
I don't recall Yanmar doing a 180?, as far as I know they have always stated the correct info. The problem has always been yanmar owners not understanding that selecting forward gear will not stop shaft rotation and that this type of rotation is a clutch mechanism slipping rather than a true neutral .
Advisory Number: MSA08-003:
DATE February 8, 2008 Dealers and OEMs
TO: All Marine Distributors
SUBJECT: Gear in Neutral While Sailing All MODELS:
All Sailboat Engines
We continue to get questions regarding the correct gear position while sailing with the engine OFF. This advisory is issued as a reminder; Yanmar requires that if sailing with the engine OFF (not running) the transmission shifter must be in the neutral position or internal damage to the gear or sail-drive will result. This damage will not be covered by Yanmar's Limited Warranty. Please instruct customers and dealers who deliver the sailboat to the customer, of the correct (Neutral) position for the marine gear while sailing.
If the customer desires that the propeller shaft not spin while sailing, either a folding propeller, shaft break, or other suitable device may be used. However, Yanmar accepts no responsibility for the selection, installation, or operation of such devices. Please also refer to Marine service advisory "MSA07-001_Yanmar Sail Drive Propeller Selection" for additional information.
If you have any questions regarding this advisory please contact a Customer Support representative.
Its been a while and this thread is pretty old but I thought I'd give an update.
I got Schiehallion lifted out about a month ago at Scarborough marina. I the hull 3 coats of the foul stuff, fixed a few little issues and mounted my new Flexofold prop.
If you interested here is a video about the whole process.
Thanks for updating Vernon, it's always useful when people do this and it makes the forum a much better resource. Enjoyed the vid, hope you don't have to wait too much longer before you head out...
Hey dexport/ vernon
watched your vid.
prop speed!
Just a heads up for all sb ers ,
while I was on the hard for one month I whitnesed a very large prop get covered all over with
engineering blue dye!
When asked , was told "gives better life than prop speed"
Just to put it out there for trial or comment.
Have fun on you trip.
Fair winds and fun times.
Select to expand quotestupid said..
Hey dexport/ vernon
watched your vid.
prop speed!
Just a heads up for all sb ers ,
while I was on the hard for one month I whitnesed a very large prop get covered all over with
engineering blue dye!
When asked , was told "gives better life than prop speed"
Just to put it out there for trial or comment.
Have fun on you trip.
Fair winds and fun times.
Hey mate
I had propspeed on my last boat and it lasted 3 years. The guys at Scarborough did the new one for $160, work and materials so I thought that was reasonable enough.
Select to expand quoteDexport said..
I got Schiehallion lifted out about a month ago at Scarborough marina.
Just an unrelated side question here.
What sort of fun do you have on the VHF using " Schiehallion" as your call sign???
I like boty's call sign "Pagan". It sort of spells it out with no clarification needed. 
Select to expand quotecisco said..Dexport said..
I got Schiehallion lifted out about a month ago at Scarborough marina.
Just an unrelated side question here.
What sort of fun do you have on the VHF using " Schiehallion" as your call sign???
I like boty's call sign "Pagan". It sort of spells it out with no clarification needed.
Yeah Cisco, its a bit of a mouthful. There a cheatsheet next to the radio which makes it easier. I was going to change the name but there were many more pressing things to send my time on than dealing with 3 different government agencies.
Select to expand quotecisco said..Dexport said..
I got Schiehallion lifted out about a month ago at Scarborough marina.
Just an unrelated side question here.
What sort of fun do you have on the VHF using " Schiehallion" as your call sign???
I like boty's call sign "Pagan". It sort of spells it out with no clarification needed.
wife says im not allowed to have a boat name with more than six letters for that reason
Select to expand quoteboty said..
wife says im not allowed to have a boat name with more than six letters for that reason
Smart wife....but that does not allow for names like "Comanche". "Apache" is another good one. Great names for yachts.
I also like Aztec, Inca and Temujin. There was a great looking Alan Payne design yacht in Gladstone called Hobo.
Select to expand quoteDexport said..cisco said..Dexport said..
I got Schiehallion lifted out about a month ago at Scarborough marina.
Just an unrelated side question here.
What sort of fun do you have on the VHF using " Schiehallion" as your call sign???
I like boty's call sign "Pagan". It sort of spells it out with no clarification needed.
Yeah Cisco, its a bit of a mouthful. There a cheatsheet next to the radio which makes it easier. I was going to change the name but there were many more pressing things to send my time on than dealing with 3 different government agencies.
Yes a friend of mine did the name change with AMSA, seemed to take two or three months from memory, and it wasn't cheap!
Select to expand quotecisco said..boty said..
wife says im not allowed to have a boat name with more than six letters for that reason
Smart wife....but that does not allow for names like "Comanche". "Apache" is another good one. Great names for yachts.
I also like Aztec, Inca and Temujin. There was a great looking Alan Payne design yacht in Gladstone called Hobo.
i know the boat been on the same mooring since i was first there in the early nineties always well maintained and always admired it a koonya design i've always thought of them them as the cruising version of the seabird
That's exactly why I called my current toy "Mango" can't remember how we came up with it.
