Sunday 7 July 2013

A man's got to know his limitations

Replacing Beta engine mounts
July 2013

It was Clint Eastwood who uttered those immortal words in Magnum Force: "a man's got to know his limitations".

Its a phrase which has suck with me since the 1970's, but one I have always found a little difficult to apply. Sure, I know that there are many things I cant do, but what do you do about all those things that you might be able to achieve but equally could be beyond your skills?

My approach tends to be a bit on the gung ho - "lets have a go" end of the spectrum - tackling practical tasks and relying on my instinct to see me through to a positive conclusion. Nine times out of ten this enthusiasm and a practical bent is enough, and when I fail I try to see it as a learning opportunity.

This weekend offered me one of those 1:10 learning opportunities.

Our Beta 38 is now nearly 10 years old and have run for about 4,000 hours - but whilst it has run faultlessly to date it is starting to need some running repairs. The last year has thrown up a bit of vibration at idle speed which has been diagnosed as worn engine mounts where the rubber has lost its texture. So new mounts were purchased at about £25 a pop having examined their construction I figured out how I would go about the task of DIY replacement.

A new Beta engine mount

I figured that I would just replace the two back mounts to start with, keeping the engine aligned longitudinally and measuring the distance between the runners and the engine brackets to ensure the vertical alignment was correct. Of course, things didn't go quite according to plan and I tried to unscrew the studs from the foot pads they just rotated in the mushy rubber. This wasn't entirely unexpected and I then resorted to the trusty angle grinder to cut through.

An extracted mount (note the mushy rubber)

Extraction was fairly simple but I initially made a stupid error as I screwed the studs down into the new feet. I screwed them down too far and bottomed them out on the bearers, negating the flexibility of the rubbers. However, lifting the studs didn't fully solve the problem but I set out on a short trip more in hope than confidence. 

The screw in stud

We had only been moving for 40 mins and things were clearly not right. The vibration was bad and varied at different revs, but there was no sweet spot on the throttle. I lifted the deck boards and was confronted with a smoking stern gland - I had clearly completely messed up the alignment big time. My problem was that I didn't know if the engine should be lifted or lowered so I was, as they say in the trade, well and truly stuffed.

Two engine mounts in

And so came the moment when the man realised his limitations. I didn't have the tools or the expertise to dig myself out of this particular hole. When the boat's bust who you gonna call? RCR of course! I use the RCR retainer scheme as I rarely need their services but I do appreciate the peace of mind of knowing that there is someone out there who will come to my rescue should the need arise. 

RCR confirmed that an engineer from an agent boatyard would be with be in 40 minutes and sure enough it wasn't long before the Oxley Marine van came into sight. Oh the relief of an expert when you are in a tight spot! The engine was too low on the mounts and its weight was being bourne by the stern gear resulting in a severe dose of over heating.

An angel in a green boiler suit!

With the benefit of many years of experience the mounts were loosened and the engine edged this way and that till the prop shaft was dead centre in the stern tube and all was running smoothly.

With the mounts tightened up the grease tube was reconnected (had melted off) and the packing tightened and we were good to go.

The hour spent with the engineer was a masterclass in boat transmissions, almost worth the call out fee! Sure I feel a bit daft having got it wrong, but I have learned and next time my limitations will be that bit further away. You live and learn.


Nev Wells said...

Phil sorted out our alternator problem. He is a real engineer and does like to do a good job. I hope you had the tea and one ready for him, we found he worked well under tea conditions !!


Andy Tidy said...

Oh yes - tea helped as much as grease!Good chap.