Beneteau 311 std prop specs

Aug 20, 2013
173
Beneteau 311 Port Clinton, OH (Lake Erie)
My 2000 Beneteau 311 came with a Michigan Sailer 14RH9 prop. I have attached a picture of what appears to be the label for the box, which came with the boat manuals. I bought the boat used in 2013 from the original owner so it's possible that the prop was changed. To reduce drag, I bought a 2-bladed Flexofold prop 3 or 4 years ago to replace the fixed prop. The Michigan Sailer prop seemed to be sized well for the boat and engine.

If you're thinking of replacing the prop or trying a different one, be aware that the boat has a metric shaft, 25 mm, not a US 1" shaft. Also be sure not to lose the rectangular key that fits in the keyway on the shaft. I found that it took a pretty strong prop puller to get the prop off the shaft.

When you have the prop off, you may want to consider replacing the cutlass bearing while you're at it. It's not hard to do but the parts are a little tricky to order, especially the little nylon screws that hold the cutlass bearing in place. You will want to replace the screws along with the bearing.
 

Attachments

Feb 16, 2020
3
Beneteau 311 Treasure Island
My 2000 Beneteau 311 came with a Michigan Sailer 14RH9 prop. I have attached a picture of what appears to be the label for the box, which came with the boat manuals. I bought the boat used in 2013 from the original owner so it's possible that the prop was changed. To reduce drag, I bought a 2-bladed Flexofold prop 3 or 4 years ago to replace the fixed prop. The Michigan Sailer prop seemed to be sized well for the boat and engine.

If you're thinking of replacing the prop or trying a different one, be aware that the boat has a metric shaft, 25 mm, not a US 1" shaft. Also be sure not to lose the rectangular key that fits in the keyway on the shaft. I found that it took a pretty strong prop puller to get the prop off the shaft.

When you have the prop off, you may want to consider replacing the cutlass bearing while you're at it. It's not hard to do but the parts are a little tricky to order, especially the little nylon screws that hold the cutlass bearing in place. You will want to replace the screws along with the bearing.
Thanks for the feedback. I don't seem to get enough boat speed at cont rpm. I have a 2-blade 14RH9 prop. I'd like to get better than 6 knots @ 3000rpm. Thinking of changing the pitch. I'm pulling the boat out next week and will check the cutlass bearing but was changed out in 2017.
 

Attachments

Aug 20, 2013
173
Beneteau 311 Port Clinton, OH (Lake Erie)
If you have a 2-bladed prop compared to my 3-bladed prop I can see how your boat would feel underpowered. Perhaps my experience will give you some guidance on what to try with yours. We might be able to negotiate the sale of my prop, but be forewarned that a 3-bladed prop would probably have more drag.

I see you have added a donut "zinc" anode in addition to the one at the end of the shaft, and the donut appears to be showing some corrosion, but not very much. Is your donut made of zinc? We often use aluminum or magnesium here in the Great Lakes because the zinc is less active in fresh water. When I purchased my boat it had only the zinc at the end of the shaft. The boat was sailed on Lake Michigan, which is cold enough that anti-fouling is sparingly applied and often not every year.
 
Feb 16, 2020
3
Beneteau 311 Treasure Island
If you have a 2-bladed prop compared to my 3-bladed prop I can see how your boat would feel underpowered. Perhaps my experience will give you some guidance on what to try with yours. We might be able to negotiate the sale of my prop, but be forewarned that a 3-bladed prop would probably have more drag.

I see you have added a donut "zinc" anode in addition to the one at the end of the shaft, and the donut appears to be showing some corrosion, but not very much. Is your donut made of zinc? We often use aluminum or magnesium here in the Great Lakes because the zinc is less active in fresh water. When I purchased my boat it had only the zinc at the end of the shaft. The boat was sailed on Lake Michigan, which is cold enough that anti-fouling is sparingly applied and often not every year.
I sail down on the west coast of Florida The shaft zinc collar was added for additional protection. If I upgrade to a new prop, I might get a folding prop. I've had the the boat since the end of 2017. It's been an nice experience but a labor of love as they say.
 

Attachments

DougM

.
Jul 24, 2005
2,242
Beneteau 323 Manistee, MI
Thanks for the feedback. I don't seem to get enough boat speed at cont rpm. I have a 2-blade 14RH9 prop. I'd like to get better than 6 knots @ 3000rpm. Thinking of changing the pitch. I'm pulling the boat out next week and will check the cutlass bearing but was changed out in 2017.
I don’t think that a change in propeller pitch is going to help much. Because the design is a displacement hull, its speed is mathematically limited by water line length and six knots is just about the limit. Change in pitch is just going make the engine work harder with no appreciable gain, plus it will probably be belching black smoke. That’s just my opinion.
 
Aug 20, 2013
173
Beneteau 311 Port Clinton, OH (Lake Erie)
I agree that six knot is probably enough on a nice day, but you may want to consider whether you have enough power to go upwind at at least four knots into wind and waves. Five or six knots is easy in flat water, but when you're trying to go that last mile or two straight upwind in 30 kn of wind in a constrained area, you appreciate having enough power and prop. If your boat does OK in these conditions, you have enough prop. If she just sits there and other sailboats are going by, then you need more.
 
Jan 22, 2008
8,050
Beneteau 323 Annapolis MD
I went with a Gori 2-blade folding prop. I liked them because the "meat" of the blades are farther out, more towards the middle and end. My 2006 B323 the skeg and prop setup looks just like your 311. Probably the same hull, I believe? I have my O.E.M. 2-Blade right here, and it is a 16 x 11 for my 3YM20. I think the plan is to rev your engine in Neutral to get max rspm, then with the right prop you should be able to get the same RsPM.

If you call a prop company for help, they will get your horsepower and a few other things to give you the proper prop for your load. My boat is 13,000 pounds on the travel lift.
 

DougM

.
Jul 24, 2005
2,242
Beneteau 323 Manistee, MI
I went with a Gori 2-blade folding prop. I liked them because the "meat" of the blades are farther out, more towards the middle and end. My 2006 B323 the skeg and prop setup looks just like your 311. Probably the same hull, I believe? I have my O.E.M. 2-Blade right here, and it is a 16 x 11 for my 3YM20. I think the plan is to rev your engine in Neutral to get max rspm, then with the right prop you should be able to get the same RsPM.

If you call a prop company for help, they will get your horsepower and a few other things to give you the proper prop for your load. My boat is 13,000 pounds on the travel lift.
I have the original Michigan Wheel 2 blade and it is a 16 x11 sitting on a shelf. I had a 16 x 14 Gori for a couple of seasons, but that was over propped (I think Ron would agree). I change to a 16 x 11 Gori and the engine liked. it better. I got into the rpm range needed and the diesel quit looking like it was fogging for mosquitoes.

(Ron, If your boat weighs 13K loaded its time to clean out the wine cellar, the anchor locker, get the lost tools out of the bilge, and empty out the lazarette. The dry weight of the 323 should be around 10k)
 
Jan 22, 2008
8,050
Beneteau 323 Annapolis MD
I have the original Michigan Wheel 2 blade and it is a 16 x11 sitting on a shelf. I had a 16 x 14 Gori for a couple of seasons, but that was over propped (I think Ron would agree). I change to a 16 x 11 Gori and the engine liked. it better. I got into the rpm range needed and the diesel quit looking like it was fogging for mosquitoes.

I was just now over at a marina, and they had a 311 named Sieante from northern DE with short keel and dual rudders. The prop is a 16, but could not read the pitch.

(Ron, If your boat weighs 13K loaded its time to clean out the wine cellar, the anchor locker, get the lost tools out of the bilge, and empty out the lazarette. The dry weight of the 323 should be around 10k)
I'm doing my best to empty the wine cellar :beer:. If you have seen what I out into the boat in upgrades, you'd believe the weight.
 
Aug 20, 2013
173
Beneteau 311 Port Clinton, OH (Lake Erie)
Ron20324, I agree that 13,000 lb is pretty heavy, my B311 rates as 7800 or 8000 lb, stripped. I don't know what the displacement is loaded, but I've managed to keep the water level below the design waterline by an inch or two, even with the water and fuel tanks loaded. Perhaps the hoist strain sensors were a little off?

DougM, my B311 has a Yanmar 2GM20F, not a three cylinder. I think the F is for freshwater.

Paul Rice, I was able to find the transmission's forward and reverse gear ratios in the Yanmar manual, which helped the prop provider size the prop. For my boat, the gear ratio is 2.62 forward (possibly also marked on the transmission), and 3.06 in reverse.
 
Jan 22, 2008
8,050
Beneteau 323 Annapolis MD
Ron20324, I agree that 13,000 lb is pretty heavy, my B311 rates as 7800 or 8000 lb, stripped. I don't know what the displacement is loaded, but I've managed to keep the water level below the design waterline by an inch or two, even with the water and fuel tanks loaded. Perhaps the hoist strain sensors were a little off?

DougM, my B311 has a Yanmar 2GM20F, not a three cylinder. I think the F is for freshwater.

Paul Rice, I was able to find the transmission's forward and reverse gear ratios in the Yanmar manual, which helped the prop provider size the prop. For my boat, the gear ratio is 2.62 forward (possibly also marked on the transmission), and 3.06 in reverse.
Well, the same marina but maybe or maybe not different travel lifts read 13k. My sailing club does daysails and one or two nights on the water. I found out there are some "sailors" who have never been on a sailboat- and those who never should be. I made many changes to the boat (see the owner mods for some of them). Several years into ownership I counted 54 upgrades and/or changes to simplify things for crew. There have been more since then, for sure.