Prop problems

[gerrysailing]

Hi

I own a Beneteau 36CC fitted with a 28hp Yanmar Engine, the performance going astern is hopeless, it simply has no power or manoverability, has anyone else experienced this problem? could it be a wrong prop fitted or wrong gearbox ratio?

Regards

Gerry

 

[Ross]

You must tell us more! I back my 30 foot Islander dependably with some prop walk. I have ten hp 3:1 gear box and a 3 blade 13x13 prop.

 

[Stu Jackson]

Most people who have problems going backwards never give it enough throttle. The boat needs to be moving to get the rudder to work. I agree with Ross, doesn't matter what engine you have, it's what prop you have.

 

[sailingdog]

It'd really help if you said what type, diameter and pitch prop you had and what gearbox you had...

Hi

I own a Beneteau 36CC fitted with a 28hp Yanmar Engine, the performance going astern is hopeless, it simply has no power or manoverability, has anyone else experienced this problem? could it be a wrong prop fitted or wrong gearbox ratio?

Regards

Gerry

 

[Steve Dion]

Not having the right prop is a major issue with factory installed props. If you know your specs, you can contact a prop shop and share your data with them for some insight.

You post does not really explain what your problem is other than "no power" or "maneuverability".

 

[Glenn17467]

There was an article last month in Sail regarding manuverability going in reverse. It related to prop/rudder relationship. It helped me understand why there is little control. Stu has it right, give it more throttle. Go straight back, get momentum, neutral, then steer. From reading the article and looking at my photos when the bottom job was done, I can see there is too much distance between the prop and rudder in a C30 for them to work together without disengaging the prop. Anyway, you need enough speed to get the rudder to bite and disengage the prop to eliminate prop walk.

 

[Steve Dion]

Glenn:

Also to add to the problem of prop walk is the distance between the tip of the blades and the hull. The prescribed distance should be in excess of 15% of the props diameter (if I remember correctly) and more is better.

Give her some juice to get it moving and then back off the throttle to maintain control.

 

[Ross]

Sometimes you have to shift to forward, put the rudder hard over and go full throttle for about 5 seconds to kick the stern left or right and then go back to reverse.

 

[Cobra]

Gerry what prop do you currently have? I'm going to guess a two blade. Any idea what pitch/diameter?
How much motoring do you do (or will you do in the future)?

I honestly have Never been in a sailboat that would back up well. According to what side you dock on, the prop-wash can make docking easier. "Glen17467" is dead on.

From my experience most prop shops are more knowledgeable about stink-pots. The best info you're going to get if from people who have similar boats. (weight/hp/keel)