Engine Mount Studs

[stevd]

I have decided to change my very worn engine mounts for my Bukh DV20 whilst the engine is out of the boat. Unfortunately the studs in which are glassed in to the hull of the boat have become loose. They are still solid in terms of movement, but they now rotate when I try and put the nut on to tighten down the mount. I feel if I can tighten the nut down, the stud will hold the mount fine.

There isnt quite enough room to get a set of mole grips on there. I thought about putting a bit of epoxy around it, but then the mount wont sit in the right place.

Any ideas, or i it easy enough to replace the studs?

 

[scottie]

How far do the studs protrude when engine is in place?

 

[stevd]

Not far, they are probably only 20mm length in total!

 

[oldsaltoz]

One would like to think the designer added a captive stainless nut for the threaded rod, have you tried a double nut or lock nut?

Whith perhaps a socket on the top nut and a ring spanner on the bottom nut?

Godd luck and fair winds.

 

[Puggy]

Sounds like the studs are actually bolts threaded through a plate that is laminated into the hull: still structurally sound, but the vibration of the engine has freed the bolts from the resin holding them tight and allows them to rotate? How about carefully grinding around the bolts as best you can with a Dremel or similar, making a "pot" around the base of the bolt with some sort of putty and pouring some epoxy resin around the base of the bolt? This would seep down and secure the bolt against being rotated. It might be worth putting a spacer on the bolt once the resin is poured and tightening a nut up onto the bolt so that the epoxy sets in a "loaded" position to prevent it cracking when put under load.

Good luck. Puggy

 

[stevd]

Unfortunately a locking nut wouldnt work as there isnt enough length. thanks for the suggestion though.

Puggy - Thats exactly what I think has happened. Your suggestion sounds like it could work...if only I had a steady accurate hand for a delicate operation....but I can find someone who can. Im good when force is needed, but when it comes to a careful steady hand to not trash the stud threads...not so much.

Cheers

 

[septiclecky]

Unfortunately a locking nut wouldnt work as there isnt enough length. thanks for the suggestion though.

Puggy - Thats exactly what I think has happened. Your suggestion sounds like it could work...if only I had a steady accurate hand for a delicate operation....but I can find someone who can. Im good when force is needed, but when it comes to a careful steady hand to not trash the stud threads...not so much.

Cheers

Have you tried a half nut?

 

[stevd]

it wouldnt be possible with that either unfortunately, I dont think the stud is quite long enough :-(

 

[vyv_cox]

Something a little unusual is going on here, I think. I cannot see a reputable builder glassing in studs or bolts that cannot be removed for the entirely expected reasons such as corrosion, stripped threads, etc. It may be that there are nuts or possibly plates inside the moulding, if you are certain that you are not looking at bolts with their heads inside a recess. Whichever it is you are in the ideal position to deal with it properly while your engine is out. You may find that a metal detector will help you to decide exactly what is there, followed by some drilling to sort it out. You can guarantee that if it is not refurbished properly the time will come when it comes back to bite you.

Can you not find an answer from owners of similar boats?

 

[stevd]

I no longer have access to the moody owners forum, I think I forgot to renew :-(

Definitely no access to them without doing anything invasive. it is a nuisance because they are still sturdy, just spinning in place.

Unfortunately I have only just found this problem. I have been waitng for my engine to be refitted by the busy engineer for the last 4 weeks, it is supposed to be fitted at the end of this week. I really dont want to miss my slot and have to wait another 4 weeks! :-(

 

[scottie]

Could you Try running a nut down on the stud then cutting a square at the top to enable you to get a spanner on to hold it?

 

[cimo]

....or cut a slot in the top for a flat head screwdriver.

I've come across 4 inverted blots myself these past 24 months. extremly annoying.
My engine mounts are fixed with coach bolts thankfully.

 

[stevd]

That could work....right another trip to the boat is in order to see which suggestion is best.

You would think they would have made access to replace them. Ah the simplest of things are always the most complicated.

 

[charles_reed]

Something a little unusual is going on here, I think. I cannot see a reputable builder glassing in studs or bolts that cannot be removed for the entirely expected reasons such as corrosion, stripped threads, etc. It may be that there are nuts or possibly plates inside the moulding, if you are certain that you are not looking at bolts with their heads inside a recess. Whichever it is you are in the ideal position to deal with it properly while your engine is out. You may find that a metal detector will help you to decide exactly what is there, followed by some drilling to sort it out. You can guarantee that if it is not refurbished properly the time will come when it comes back to bite you.

Can you not find an answer from owners of similar boats?

It was a horrible habit of Westerly(though I appreciate the boat was not made by them) to simply glass in a bolt which then rotated just as you describe. However, as Vyv, suggests it's one of those nettles you have to grasp.
Assuming the studs are glassed into engine bearers, the proper solution would be to cut them out, and glass in a properly fabricated plate.
I had to do just that when I changed from 2GM to 3YM engine and it was remarkable how quick and simple it was to do a job I'd been dreading.
As the Bard says "'Tis our fears that makes cowards of us all"

 

[stevd]

Ok problem solved thanks for the help.

Who said moody's were built well? It was a bolt glassed into the bearers. No fixing plate. i suppose it has lasted 30 years, but I still think it is a little poor.

Used a hole saw into the side of the engine bearer to gain acces to the bolts, once that was done it was a simple task of replacing for new with a backing plate, bonded the circle 'plug' back in place, job a gud 'un. Simple and straight forward, but I must admit I was hoping to get around it without cutting, but it was nothing like what I was expecting! Weird how you can dred doing something and it turns out to be incredibly simple, then other tasks which you are sure will be simple never turn out that way!

 

[vyv_cox]

Well done, I'm sure you won't regret having it right.