Jenneau 49DS

[ccscott49]

A friend of mine has one of these boats from 2006 down here in Corfu, his Gori prop is stuffed due to electrolitic corrosion. Has anybody here replace the prop with a fixed three blader and if so, what size and pitch please? Shaft is 35mm. Have tried Jenneau and they are very little help, just saying we fitted Gori and nowt else! Help!!

 

[coopec]

After talking to an engineer there are a lot of tapers but there are certain standard tapers. Who's to say yours is "standard"though? View attachment 70002


Did you have a look at this thread on ybw?
http://www.ybw.com/forums/showthread.php?200427-Prop-shaft-taper

Have you have already contacted Gori?

https://www.google.com.au/search?ei...3k1j0i13i30k1j0i22i30k1j33i21k1.0.XYVkppY0Kc0

Clive Cooper

 

[KellysEye]

The problem he will have is if he fits a new prop it will happen again the only solution is to move to a new marina. I searched for the prop type and can't find it.

 

[RichardS]

The problem he will have is if he fits a new prop it will happen again the only solution is to move to a new marina..

Please could you explain why this is the only solution?

Richard

 

[maby]

Please could you explain why this is the only solution?

Richard

indeed - there are other ways to reduce electrolytic corrosion.

 

[coopec]

Please could you explain why this is the only solution?

Richard

I'm asking the same question. Why?

As far as size and pitch is concerned the prop supplier asked me what sort of boat, continuous HP rating of the motor (39HP) and cruising revs (3000 RPM) as well as the gearbox ratio (2.1). He put the details into a hand held computer (calculator?) and said the BW gearbox was no good and I would have to find a 2.5/1. I later told him all I could find was a gearbox with 2.9 ratio. He phoned me back and asked If I could swing a 21 in prop and when I said I could he said to grab the 2.9/1 box. He said it would be close to perfect because they strive for 87%(?) efficiency and my set-up would be 85%.

 

[Bobc]

19 x 15 will be about right for a fixed 3 blade. That's what I have on my Bav49 with a TMD22 engine.

 

[Tranona]

Suggest you put the yacht data into the Propcalc programme on www.castlemarine.co.uk for a good guide. however if he is buying new then just provide the same data to the supplier then they will work it out. That way the onus is on the supplier to get it right (which they usually do). There are many such suppliers in the UK. Suggest you start with www.lakestergear.co.uk Expect to pay between £5-600 for a fixed 3 blade of that size.

 

[coopec]

Prop shaft revolution per min (gear box ratio), engine RPM at continuous revs as well as engine HP (continuous) would be an important factors in determining the prop characteristics. Clive Cooper

 

[RobinBirch]

For a bit of general guidance look for an equivalent HP engine in the Beta Marine prop guidance PDF http://betamarine.co.uk/wp-content/uploads/downloads/propellers_guidelines/PROP-SGL-1011.pdf

 

[syfuga]

Take care.. make sure that the thread taper and length are specified. We removed a Gori (lost a blade) and replaced it with a Flexofold. Assured by Flexofold that the shaft was standard, but when it arrived and we came to fit it, the boss of the Flexofold was too deep for the taper. We had to have the new Flexofold machined out in order to fit the taper and tighten up the nut.

 

[lpdsn]

A friend of mine has one of these boats from 2006 down here in Corfu, his Gori prop is stuffed due to electrolitic corrosion.

Maybe the subject of a different thread, but you should get him to find the cause before it affects anything else. A very good chance the problem is with his own boat and will simply re-occur.