It looks like left hand. See here;

www.hhprop.com/how-boat-props-work.php

RotationThe Direction a prop rotates when viewed from the stern facing forward.
Right-hand propellers rotate clockwise to provide forward thrust.
Left-hand propellers rotate counter-clockwise to provide forward thrust.
Note: Left-Hand Propellers are primarily used on twin engine boats to cancel the steering torque that would be caused if both propellers spun in the same direction.

The photo resolution is not ideal but the blade's coatings don't look all that smooth and there are damage nicks in the leading edge. How old is the prop? It could well be the original hence 40+ years old with associated damage and coating roughness. Is the shafting aligned suitably hence avoiding excess stern tube and p bracket friction which will soak up a bit of torque - albeit the misalignment would have to be a fair bit to have this issue. Suggest your mechanic check the alignment when he is on board - if you can uncouple and turn the propshaft by hand this will indicate any problems associated with this. If the bearings are excessively worn allowing the prop and shaft to shake laterally this won't help - again it would have to be reasonably bad and would also show up in bad vibrations. Is the coupling ok?

Not possible to advise the diameter and pitch from the photo - as above these will be stamped on the prop hub somewhere.

Propspeed coating would give a smoother blade surface than what you have now but won't address the nicks and other accumulated damage.

If you are going for a new prop suggest look at 3 blade folding or feathering prop which will give better speed under sail also - see the Austral website. Maxprop do a 4 blade feathering but cost would be an issue. Kiwiprop could be cost effective. But I agree you need speed under power as the priority. Austral have a page on "specials" at reduced cost but no good buying something at reduced cost if it is not suitable.

Hi, Porters at Parramatta I have found to be easier to discuss options with, and their ballpark price was better too.

Thanks guys

Hey Guys,
Austral has replied. Please find screenshot.

D H Porter get glowing reviews from many of my fellow members of the Compass Yacht forum. Nevertheless I had good service from Austral.

Why does Austral's quote size the prop at 2000rpm? Doesn't it rev up to somewhere around 3000? That prop has a bigger diameter and pitch than my prop, which is powered by a 13hp Yanmar 2GM.

I have no idea what is going on. 100 people 100 opinions. I just hope that mechanic will manage to adjust correct new propeller and I will hopefully get that full hull speed on 6.25 knots once the boat is antifuled and prop is speed proped too.... currently 4.5 knots but it just doesn't sound right!

Keep in touch

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Serb1980 said..
Finally photo.....this is a photo of the propeller. It was taken a year a go during antifuling. Yesterday took the boat for a spin. 4 knots Max. Something is not right. Hull is not that dirty. Next week a mechanic will jump on board to see what is going on. I think he will measure the revs and try to improve the speed once the boat is out on 1st December for antifuling.
It would be so cool to reach the speed of 6 knots.....if needed when wind is quite or none at all.. please guys can someone comment it this propeller is 15x12 and is this is left of right... A worker at Austral told me that with my engine yse8 and propeller 15x12 3 blade boat should get 6.5knots..
Any thoughts? Buy the way a propeller is around 1200 bucks at Austral.
Thanks

G'day Serb,
It does sound like the prop is either too small or not enough pitch on a little engine...but.......as mentioned above, I wouldn't get too stressed about trying for max hull performance under motor. It's a sailboat. The iron engine will always be secondary to the sail engine for performance. You may just have a plugger until you can work out the best prop, but that doesn't effect you trying to hit your numbers. .
Even a single sail trimmed well can often outperform an 'iron sail' . With two sails up, there is no competition, sail wins every time.
If you're looking for your maximum speed, turn off the engine and focus on your sail trim, it'll be much easier and quicker.

Edit: and 100% on the clean hull, Once a month is awesome if performance is important to you. If I left a clean go for 2-3 months the impact on performance was easily evident, under motor and under sail. If you're not interested in performance, the cleaning schedule typically blows out to many months and you get the resultant drop in speed, horses for courses 'n all.
Cheers,
SB

With 100hp a 22" prop at 2.5 : 1 gets me 5kts & 1200rpm and economically that's clean of course more engine speed the temp gauge goes up and the fuel gauge goes down for 3/4 of a knot, I much prefer to sail

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wongaga said..
Why does Austral's quote size the prop at 2000rpm? Doesn't it rev up to somewhere around 3000? That prop has a bigger diameter and pitch than my prop, which is powered by a 13hp Yanmar 2GM.

Would the answer be related to the gearbox ratio? My prop is rated for 3000 RPM on a 2:1 gearbox. Austral's quote relates to a 3.22:1 gearbox. Maybe Wongonga's gearbox ratio is nearer 2:1?

Guys I am paying a diver to take an old propeller so I can bring it to Austral to fix the bore on a new recommended propeller 15.5 x 12. It is painful to cruise 5km/h with engine screaming like crazy. On Tuesday next week propeller is out and on Thursday I will be having a new propeller to fit it back. Austral promised 6.5 knots, way better than 5km/h...
I will keep you posted. The price is 1200 bucks for a new propeller from Austral and diver will take 150 bucks for his work ...
I will let you know how I go,next Thursday once a new propeller us back

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garymalmgren said..
Hi Serb.
First of all, your boat is a sailboat. The engine and propeller are added on. They are not the main driving force, so they are not as efficient as you expect.

Second, a YSE 8 is a very small engine. And old. That means the engine will probably not be producing full power anymore.

Next, I have a 25 footer with a good YSE 12 and a two bladed prop. I think your boat has had a two blade prop since new. That was what the designers chose. Even with a coat of PopSpeed or something like that , the propeller will foul up much faster than you expect and as others have said even a couple of small barnacles will make a big difference. A new 3 blade propeller will also foul quickly.

You mention vibration.
Welcome to the world of a YSE engine. These engines are the worst in the world for vibration and you will never get rid of that.


The difference between motoring in calm water and rough water, motoring into the tide and against the tide is great.
The difference between a clean hull and propeller and a slightly dirty hull and prop is great.

So, you have a sailboat with a small old engine and a dirty hull and prop. That means your boat will be slower that its top speed, but it also means your top speed (in knots or kilo/hour ) will be lower that you expect.

Don't buy a new 3 blade prop. Control your fear of sharks, dive in and clean the prop with a scraper an a scouring pad and go sailing.

PS. You mention that the engine is noisy. I wear earplugs if I have to motor more than an hour or so.

gary

My dear friend, you where right here when you sad that my YSE 8 is old and not producing 8hp. After changing an alternator and connecting the alternator belt the engine is struggling to start and almost impossible to achieve full revs..
now in process of rebuilding it.
keep in touch