Loose engine mounting bolt

[SimonA]

While trying to sort another problem I discovered one of the engine mounting bolts (rear of engine near gearbox) is not actually supporting the engine. The bolt looks like it's at a strange angle and the engine foot is vibrating around as it's not held tight.

So can I just put a new bolt in and tighten it, or is it likely to be more involved? I'm also worried what this might have done to the alignment of the prop shaft, hopefully the weight of the engine has kept everything aligned.

Also what is that under the bolt. (Engine is a BMC 1.5)

 

[dickh]

Aaagghhh!!!! Been there done that! You will have to lift the engine out(or maybe support the engine and remove the bracketry) - the rubber mount is a down facing doughnut which is recessed into a hole in the engine mounting beam. The rubber has seperated from the metal and the whole lot is rotating. The only solution is to replace the mount, and probably the others as well. A bad design in my view as you cannot see the rubber and it only needs a little diesel or oil in the recess and it b******* up the mount! I got over it by replacing the engine, which was totally knackered anyway. Good Luck!

 

[Guest]

My loose engine bolt ended up causing serious damage as it was the one that couldn't be easily seen.

Usually they are fitted through a composite body of rubber and metal ... the rubber separates later in life and mount fails. Engine then is allowed to move and strains shaft, coupling and stern-seal. If left can lead to serious work needed.

I suggest you get it fixed and it's generally not advisable to replace one or two ... better replace all and be sure all is ok.

(My little lot cost me near £3000 to put right ..... new bearers, mounts, shaft, coupling and re-mount stern-seal)

 

[SimonA]

[ QUOTE ]
(My little lot cost me near £3000 to put right ..... new bearers, mounts, shaft, coupling and re-mount stern-seal)

[/ QUOTE ]

/forums/images/graemlins/shocked.gif

Oh dear. That does not sound great. I was rather hoping it would be a simple job.

 

[Guest]

Exactly .....

Couldn't see the bolt .... kept eye on engine while in use etc.

Noted engine start to move on beds .... had boat hauled and checked. Engine movement had caused the remaing 3 mounts to start to fail. The movement had strained the stern-seal mount and caused grooving of the shaft.

The person who fitted the engine originally had fitted Beach bearers with bolts inserted from below before mounting bearers. Meant that bolts could not be withdrawn. Engine could not be lifted of bearers as height needed to clear bolts was not available. Therefore engine surrounding structure had to be cut and removed. Coupling and shaft were seized solid after near 25 yrs use .... so had to oxy-torched and cut. Engine slid forward into cabin and then lifted with bearers. Once out of boat - bearers were then cut away.
New angle iron bearers fitted allowing insert / remove bolts for engine mounts.
Old coupling and shaft were condemned ... along with stern-seal mount.

So by time all back in place - a serious amount of work had been done. Which a few years later actually paid of in advantage when we replaced engine ... replacement having same mount config. slid straight in ....
Yes my bill was higher than most would pay - hopefully, but imagine the work involved !

Seriously - get it sorted before it costs you really dear !!

 

[AndrewB]

Re: Exactly .....

Sounds a bit of a disaster. Flexible engine mounts are like tyres, they are expendible items that are bound to need replacing from time to time during the life of the yacht. Any decent yacht should be designed so the engine can be lifted off them without quite such a major operation.

The tricky bit is realigning the engine afterwards, but it can still be a DIY job.

 

[Guest]

Re: Exactly .....

Problem was the twit shoehorned a girt big bus engine into a small hole. He also used Petter Mounts on a 32HP Perkins !! Amazing they lasted 25yrs ! The guy obviously never imagined he would ever have to sort later ... in fact he didn't - it was 2 owners later ....

If the engine had been a better suited size then a lot of the trouble wouldn't have been there ... but at least I know with the engine in there I have - I will get home on time.