Marquipt Davit - Turning When Loaded

[JLR]

Why not another project. For those experienced with Marquipt Davits, I have a 1200 pound Davit that can go up and down and also where the wire can go in and out. However, it is not one where it can spin on its axis by power. So, when I am raising my 16 RIB,, and the RIB is parallel to my boat, it is extremely difficult to spin the loaded davit to swing the dink so that it is perpendicular to the boat. I need to lower it and raise it along side because the reach of the arm will not let me lower over the aft end. Aside from some sort of makeshift pulley system, is there an easier way to be able to spin the davit when she is fully loaded? I do not think taking it out and greasing it will make any difference and I am loathe to rig up a pulley system for fear that it will simply put more of a downward load on the arm ( which must remain at no less than a thirty degree angle to the hardtop under load). Also, for you physics majors out there, including Dr. Jim, should it be easier to spin the closer the dink is to the top of the davit or when it is just off the water? If I was any good at physics, I would have gone to med school not law school. Thanks.

 

[Dan Mapes]

Short of pulling it apart, if it goes onto the hardtop bow first, put a line in the bow ring that is long enough to reach up to the hardtop with some slack. As it comes up retrieve the line. When you are ready to rotate the davit pull on the line. Alternatively attach the line to another point or cables on the davit. I am thinking you could also clip a line onto the lift cable with a stainless caribiner attached to the line.

At least you will know if it will give you leverage you need.

 

[JLR]

Thanks Dan. When hoisting, I have been using two lines, one on the bow and one on the stern of the dink. Even with those lines, it has been a bear to try to turn the davit. Perhaps a line attached to the end of the davit as well- sort of like the caribiner idea. I'm 240 and the mechanic is 170 and together it took twenty minutes of yanking to try to get it to turn including pulling from the swim platform and the hardtop. I can't imagine that this is normal.

 

[z28jimi]

I have a similar problem, and was told by the folks at Marquipt that I probably needed to replace the bearings inside the davit housing. Haven't done it yet, so I can't comment on whether that will solve the problem or not, but it might be worth looking into. Also, is the standpipe vertical? If it leans to one side or the other due to a list, that will make a difference.

 

[Dan Mapes]

Well I guess Marquipt gave us the answer. If I went that far I think I would add a zerk fitting but the notion of grease melting down onto the hard top is not very appealing.

 

[SKYCHENEY]

Is the standpipe plumb? If not, it will be very difficult to turn. I have this problem as well and the line on the end of the davit helps but it is still a chore. I plan to relocate and replumb the stand pipe. I may even canter it inward to help the situation.

 

[Dan Mapes]

If there is "stiction" when it is not loaded that is going to be magnified under load. Is the rotation of the davit smooth and free unloaded?

 

[JLR]

Thanks all. First, the davit turns quite freely when not loaded. Second, when the dink is on the davit and outboard of the boat, the boat does list with the weight of the dink. Third, mechanic was told by Marquipt that drilling and putting a grease fitting was a bad idea as he might hit the bearings. Fourth, as far as I can tell, the standpipe is plumb. Although we have no answer yet, somehow it is nice to know that others have the same problem. I do not want to mount anything permanently on my hardtop to address this problem but is there something like an electric come along that might work? I do have pad eyes up there that could be used on one end.

 

[MikeP]

I think the "problem" is simply the weight of the dink. IOW, there's nothing really wrong with anything but the heavier the dink, the more difficult it is to turn the davit. We have an 11 ft Avon inflateable/fiberglass bottom/deck dink with a 15 HP 4stroke outboard. I don't know the weight but we remove/replace it the same way with the same davit - over the side and with a fore and aft line on the dink.

I could tell a noticeable difference in the ease of maneuvering the davit when we switched from a 6HP 2 stroke motor to the 15 - about 75 lbs heavier plus the starting battery - maybe a total of 85-90 more pounds. It used to be easy, now it's somewhat more.

However, it DOES feel to me like cleaning/re-lubing the davit bearings might be helpful. I would probably do that IF I could figure out how to get the davit off the post by myself. Since I have no sky hook available, it's not workable for me. There is no sign of the bearings being bad - no roughness at all but I'm confident it's never been worked on after installation when the boat was new so I'd bet that cleaning the bearings/re-lubing would be helpful. If you have someone to help you pull it, I'd do the clean lube. I have no idea how much the davit weighs but I don't think it's all that heavy. Worst case...nothing's changed but it might help.

 

[JLR]

Thanks Mike. I would be the helper and the mechanic would be the other person. The dink is quite heavy- my guess is that with the 90hp motor it is close to 900 pounds or so. How accessible are the bearings to re-lube once the davit is off? If easily accessible, it might be worth it. If not, I am hesitant to fiddle with the workings of the Marquipt davit.

 

[rsmith]

Sometimes you need to lube the shaft to keep things spinning!

 

[z28jimi]

With a couple of people working on it, the davit comes off fairly easily, but…be VERY careful of pinch points. Once it's off the standpipe, the head and the arm will want to go their own ways, and it's easy to get fingers caught. The bearings are just a couple blocks of Delrin-type material held in place with roll pins. I had a devil of a time getting the pin for the lower bearing out, and was unable to remove the pin for the upper bearing. There is also a flat plate up inside the davit head made of the same type of material that rests on the top of the standpipe. I greased the whee out of mine, and could see no appreciable difference. I agree that weight of the dinghy is probably the biggest factor. I'm looking at an aluminum bottom RIB to replace my Avon in order to drop about 100#.

 

[saltshaker]

Thanks Mike. I would be the helper and the mechanic would be the other person. The dink is quite heavy- my guess is that with the 90hp motor it is close to 900 pounds or so. How accessible are the bearings to re-lube once the davit is off? If easily accessible, it might be worth it. If not, I am hesitant to fiddle with the workings of the Marquipt davit.

My 14' Avon with 59HP 4 stroke is around 1000lbs. Yours may be much heavier.

 

[northshoreone]

I have the same issue with mine and lift a 13 ft Whaler with a 40 hp engine. I made a line that hooks one end on one of the fly bridge dingy tie down eyes...the line runs through a small pulley attached to a short line clipped to the aft end of the whaler then back up to me. Once the whaler is high enough to swing around to the boat I have a loop with a spring snap ring measured just the right length coming off the bow line of the dingy. I hook the loop in the line around the davit height adjustment arm which allows me to pull on the aft line with the pulley without the boat just turning in the air and the davit staying put. Using this method I can pull it around by myself. Without this set up, your correct it takes allot of effort to pull that weight around! My davit swings just fine without the weight on it...its the 1,000 lbs with a bit of a list to the boat that makes it so tough! This method works great for me even in the wind.

 

[MikeP]

Re the bearings - I have never pulled the davit so I don't know anythings about the bearings.

HOWEVER, if they are Delrin or something similar, I have had really good luck with lubricating them with silicone grease (di-electric grease is the same thing). I had some cheap helm chairs that you could barely get to rotate while sitting on them. Lubing them with silicone grease made them extremely easy to rotate.

 

[Artzco]

I have an Avon 12' center console with Yamaha 40 and when I first raised it with the Marquipt lift, it was very difficult to swing in even with 2 lines on the dinghy. When we pulled the davit off in 2013 to have the RAM repaired, we cleaned the tube & inside the davit and put a good coating of silicone grease on everything we thought would touch when the davit swings. Since then, even with my heavy dinghy, it swings smoothly.

 

[JLR]

Thanks everyone fo thir help. I might rig up a pulley system, as discussed, and give that a try. Rigging one end of the pulley to the dink should solve my problem of any real downward drag on the davit arm if I wait until the dink is just level or a bit above the hardtop. Grease seems a little hit or miss.

 

[saltshaker]

This is why I'm happy the PO installed a fully hydraulic 1700lb davit. All motion is controlled by a remote.

 

[Angela]

Re the bearings - I have never pulled the davit so I don't know anythings about the bearings.

I've had mine off a couple of times, replaced the motor and cable, and never found any bearings inside. I can say that re-greasing did not help one bit with lateral movement. I have a line on the bow of the Hober that I use to pull, together with a lasso around the tip of the davit arm. Once I get the least bit of movement going, it's not too bad. Not easy, though.

 

[JLR]

Ang - thanks. I think my problem may have been trying to pull from the aft end of the dink rather than a line around the tip of the davit. I agree. Once it gets going, it turns easily. As soon as I study up on pulleys I might just make a portable setup to keep handy when trying to lift the dink back up and spin it.