outboard lifting eyes/sling - drilling through housing

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Skipperey

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I have a 20HP Honda on my 3.5m rib dinghy and want to be able to lift the outboard aboard easily, in vertical orientation, for mounting on the rail when the dinghy is carried offshore in davits.

I have a good crane/block setup that works well for the lifting and lowering, but I am currently using a heavy duty nylon lifting sling for the outboard, and it is less than satisfactory.

The problem: the nylon sling fits around the housing and over the cowling, and is fiddly to fit and secure. If I leave the sling in place, it degrades in the sun and prevents checking the engine oil level. If I fit the sling only when needed, it is time-consuming and awkward.

The possible solution: I am thinking about drilling two holes in the aft corners of the housing (below the join with the cowling) and attaching two eyebolts. I will then make up a rope sling that can be shackled to the two eyebolts and to the forward lifting handle of the engine, in tripod fashion with a lifting eye at the top. The sling will be easily removable/mountable/stowable, and I believe that the solution overall will be strong, secure and convenient.

The question is, has anyone had experience of drilling through outboard engine housings for this kind of thing? Anything I need to be careful of?

It seems to me that it should work. The eyebolt hardware will be in A4, and the eyebolts will be held with nyloc nuts and penny washers outside and inside, to ensure that the load is spread and secure. I will use Sikaflex against water entry and can use nylon spacers and/or paste to avoid contact between dissimilar metals.

I am inclined to go ahead and do this, but I have not seen it done, so thought it worth asking the community here if anyone has relevant experience or thoughts to offer!

Thanks,
Skipperey
 
I don't have much experience of engines of that size - but is the housing really strong enough (and well enough attached) to lift the engine by it? I'd want to fit my slings to something a bit more structural.

Pete
 
Skipperey said:
I am inclined to go ahead and do this, but I have not seen it done,
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There will be an excellent reason you haven't seen it done. The cowling isn't designed to support the motor's weight. It will be under great stress during the lift and the reason you probably haven't seen any is that those that have been modified like that are resting on the sea bed.
Why not make a steel strap that you can bolt across the motor under the cover. You'll have to remove the cover to use it, but that's only a moment's work.

Bigger outboards tend to have lifting eyes on the block as standard.
 
My 2stroke 30hp had an eye at the back of the engine underneath the cowling release lever. This was through bolted into the casing. It was used for the steering cable linking it to the rudders on my cat. I see absolutely no reason why you could not fit a similar eye and then use it as the securing point for slings either side of the cowling plus another on the front of the engine. I would probably not want to do it for an engine heavier than a 20hp 4stroke.
 
Thanks for these suggestions. I probably was not clear about my description. It is not the cowling that I would be drilling through, but the solid aluminium housing below where the cowling attaches -- so the cowling would remain in place, and would not be bearing any weight.

As for the suggestion of a lifting eye under the cowling, I had thought at first that this would be the solution -- but unfortunately Honda have not provided a lifting eye, nor have they provided (as far as I can see) a threaded female fitting in the block into which an eye could be fitted.

So I am still a bit perplexed about what to do!
 
You are presumably intending to mount the eyebolts on the two sections of the lower cover shown in the diagram HERE

They are cosmetic rather than structural.
You would have to look at the way in which they are attached to the main part of the engine. Are the fixings adequate to take the weight and are they strong enough at the fixing points. It does not look as though they are very robustly fixed to the main structure.

Also I imagine that you are considering eye bolts fitted horizontally through these covers.

Are you sure they are strong enough to take that sort of angled load, or can you stiffen and strengthen them adequately.

The engine weighs I believe 47 or 50 kg depending on shaft length and looks something like this
BF20_large.png
 
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Another suggestion?

Fix a permanant nylon strap horizontally around the casing ,below the cowling joint.Have "D" rings sewn into the strap where appropriate to mate up with snap shackles on your lifting hoist. This would give you proper attachment points without any drilling into the casing,and the load would be spread as it is at present with the existing sling.
The only issue would be how to fix the strap on permanantly ,without it slipping down,but I am sure that this could be easily arranged ..possibly adhesive or a self tapper here and there.?
 
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Skipperey said:
Thanks for these suggestions. I probably was not clear about my description. It is not the cowling that I would be drilling through, but the solid aluminium housing below where the cowling attaches -- so the cowling would remain in place, and would not be bearing any weight.

As for the suggestion of a lifting eye under the cowling, I had thought at first that this would be the solution -- but unfortunately Honda have not provided a lifting eye, nor have they provided (as far as I can see) a threaded female fitting in the block into which an eye could be fitted.

So I am still a bit perplexed about what to do!
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Problem with terminology.
The cowling is the shroud around the motor at the top of the leg.
The bit that removes for access is the cover.

The plate to provide a lifting point under the cover is usually attathced under a couple of the cylinder head bolts or some similar meaty stud.

Here is one, although the numpty has put the red circle a bit off-target.

S3-TopOfBlock.jpg
 
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Yes, I was considering bolting through the "lower covers", not the cover. But it seems that even this may not be strong enough (the engine is about 50kg wet). I had at first thought that the lower covers were pretty solid, but the diagramme supplied by VicS is accurate and does suggest that it may not be very strong -- so I will have to have a further look and see if something can be done to spread the load, if I go down this path.

Unfortunately there is no eye or attachment point for an eye (ie, as shown in the photo from Lakesailor). It would be great if there were, and Honda really should consider adding at least a threaded point in the block of this model, to take a lifting eye.

I am not on the boat right now, and was just looking to assemble some materials -- but I think I will have to wait until I am back in Spain and can have a further careful look before deciding what to do.

Thanks for the help. I will update this thread with a photo of the end result -- even if it is not beautiful!
 
Skipperey said:
I am not on the boat right now, and was just looking to assemble some materials -- but I think I will have to wait until I am back in Spain and can have a further careful look before deciding what to do.
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Can't you go into a Honda dealer and have a nosey? You could have it all sorted before going back to the boat.
 
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