Engine mounting bolts (help please)

[brian@calshot]

1st post and need help

I have a moody 29, the engine (a bukh dv20) needs a complete rebuild, as it is now out I decided to replace the engine mounts.

The problem I have is the 2 bolts that hold each of the 4 engine mounts to the boat are either completely rotten OR are spinnng and not coming out of the boat, so I cant remove the mounts.

The questions I have are

1. originally how were the engine mounting bolts attached.
2. Has anyone had this problem and how did they get round it
3. I have seen that people replace the engines with different models so it would probably require moving the mounts, how did they attach the mounts to the boat?

Your help in this matter is greatly appreciated.

PS My best gain with the rebuild so far is the replacement alternator BUKH wanted lots chappy in plymouth didnt, he only wanted £150 and very very helpful! Otherwise this isnt a cheap past-time but the rebuild is keeping me out of the house!

 

[Avocet]

This is a wild guess, but I'm wondering if they go into fibreglass bearers? If so, it's possible that they went into a threaded insert that was originally "glassed-in" to the bearer. Over time, the bolt has seized into the insert (probably made of a different material to the bolt) and trying to undo it has torn it out of the bearer. If that's the case, the only solution would be to drill the head off the bolt and then re-engineer something - either re-glue the insert, or make something different isntead.

 

[brian@calshot]

Thankyou. I think you are completely correct,

They are on fibreglass bearers, so your second assumption is probably right that there is some form of captive nut that has rusted and welded itself to the bolt shaft.

I need to know what the best thing is to do.

1. As you recommend the only practical solution is to drill the bolts out.
2. Replace the bolts but how can I capture them, I'm thinking drill out the bolts oversize the cavity and use butchered washers etc to try and grip the resin to the bolt, but there must be a better solution

waiting with anticipation

 

[MrCramp]

I think Avocet is correct. You will have to cut the old insert out of the fibreglass and put new ones in.
I guess you used the following company in Plymouth. They offer a great service at a good price and I am a happy past customer of their's.
http://www.startermotor-alternator.co.uk/

 

[theoldsalt]

Plenty of good (specific) advise available from fellow M29 owners on the Moody Owners Association (MOA) website.

 

[brian@calshot]

As a new member it appears my replies are having to go through a moderator

So I apologise if my replies are a little slow

I will check out the moody website and ..

yes I used them to get the alternator ...too helpful even marked up the terminals. Didnt want to link as not sure about the pimping rules

 

[saxonpirate]

Brian, don't despair there's always away around things. If the above suggestions don't work I suggest you do the following.
If you plan on putting your original lump back in but the beds are shot you can always make up some plates out of 8/10mm angle iron, drill and tap the angle to suit your new mounts and then through bolt the angle to your existing beds. This will obviously raise the beds by 8/10 mm, but you can adjust that with your threaded mounts. I've enclosed a photo below. Also take a look at my forum album for an engine change I did by clicking on saxonpirate.

As for getting those old bolts out, is it possible to get in there with a small grinder and cutting disc ?

 

[Spyro]

If the bolts are just spinning you're going to have to try and pull them out. Can you get a vice and clamp it tight onto the bolt head then use something to lever up the vice. It might cause a bit of damage to the bearer but it will be easy to rebuild as you have good access with the engine out.

 

[chewi]

1st post and need help

I have a moody 29, the engine (a bukh dv20) needs a complete rebuild, as it is now out I decided to replace the engine mounts.

The problem I have is the 2 bolts that hold each of the 4 engine mounts to the boat are either completely rotten OR are spinnng and not coming out of the boat, so I cant remove the mounts.

The questions I have are

1. originally how were the engine mounting bolts attached.
2. Has anyone had this problem and how did they get round it
3. I have seen that people replace the engines with different models so it would probably require moving the mounts, how did they attach the mounts to the boat?

Your help in this matter is greatly appreciated.

PS My best gain with the rebuild so far is the replacement alternator BUKH wanted lots chappy in plymouth didnt, he only wanted £150 and very very helpful! Otherwise this isnt a cheap past-time but the rebuild is keeping me out of the house!

I just did similar with a BUKH10 in a Cobre 750.

The mounts are original Bukh, circular tops with oval bottoms secured by two bolts each to a flat bar buried in the bearers, but you need to prove you have one too.


You will prob have to grind off the old bolts ,but don't do it yet.... use the current positions to help deduce new ones...

With the engine already out you can drill a 10mm marker hole through the M12 holes in the current mounts in situ. That drill will stop when you meet the metal bar, proving it's there , and establishing the centres for each mount.

You can now grind off the old heads, use the 10mm marker hole to position the new foot and rotate it enough to drill and M8 tap a new fixing hole, avoiding the remnant of the old bolt.
Get a decent tap, 'cos you don't want it to break in the hole.

The engine will then fit on your new bearers whch are in the same place as the old ones.

 

[Mistroma]

I bought replacement mounts for my DV20 from Robush several years ago. They were much cheaper than the Bukh original parts and were identical (apart from red paint).

I just looked up the part no. stamped on my old mounts and looked them up in the Robush catalogue. However, they seem to have an online shop now.

UPDATE: I found a copy of the old receipt and my DV20 mounts were RAB 2 E 10-00179-01
Robush have them here at £11 each excl. VAT but out of stock just now.
http://www.robush.co.uk/onlineshop/list_prod.cfm?catid=57

I might have a set of correct size bolts (engine to mount) but it's a day trip to the boat to get them. Let me know if you have problems getting the correct size and I'll check next time I go to the boat.

 

[brian@calshot]

I am desperate to thankyou all but I must seem the most ignorant person on the planet ..I am soooo sorry but I am new and all my posts have to go through the moderator

SO MANY FANTASTIC IDEAS

SO MUCH GREATFULLNESS THIS END

 

[Deleted member 36384]

I have no additional advice on the engine mounts. If you have GRP work to carry out the advice offered in West System's user guides is excellent. The methods are applicable to other Epoxy manufacturers glues as well. Link below: -

http://www.westsystem.com/ss/use-guides/

In particular about half way down the page "002-550 Fiberglass Boat Repair & Maintenance".

If you need to glass in new threaded inserts you will find good advice in the book.