My 1998 Broom 9/70 is fitted with a pair of Mermaid Turbo Merlin engines. When I purchased it last year, I had noticed that there was oil in the bilges. This could have been spilt during routine servicing, but it could equally have been something more serious. As there was nothing else much wrong with the boat, I took the chance that it was probably not too serious and could soon be put right. The engines had done around 1500 hours, but the boat had not been used much in the last three years.


I called Mermaid, whose assistance was vital in helping me to detect the source of the leak. It turned out to be the oil seal at the aft end of the crankshaft. I was advised to change seals on both engines as they had probably dried out through lack of use.

Commodore Graham Johnson and Honorary Club Marine Engineer Barry Booth volunteered to assist with this daunting task. Our first job was to disconnect the shaft from the gearbox. Fortunately I have disc type rope cutters fitted, rather than the scissors variety, so the shaft could be moved back, away from the gearbox, without disrupting the rope cutter. We marked the position of the shaft so that it would be reinstalled in exactly the same sense rotationally as it had been in before removal. Next the turbo unit had to be moved out of the way to give access to the gearbox, which had to be removed. This was simple enough for two people to lift out when the retaining bolts had been undone.  

We seemed to be getting along just fine. To get the flywheel out we needed to remove the bell housing. The bolts holding this on were easy enough to access and remove but it required us to unbolt the starter motor before we could remove the bell housing out of the way. This was an additional task we had not foreseen or planned for so it was frustrating to encounter at this stage.

Getting access to the flywheel bolts now required us (more accurately Graham and Barry) to practically fold in half and bend over backwards as well as we were now working deep into the engine bay, low down in the boat. The main cross stringers behind us restricted the available space Graham had to lower himself into the bay behind the engine. Despite Barry’s suggestions, he found it practically impossible to do this so we undid the rear mounting bolts on the engine and raised the rear end by winching it upwards about 15 to 20 cm. This improved access enough for Graham to reach and remove the flywheel bolts. The flywheel came out easily enough, revealing the plate holding the all-important oil seal.

So far it had taken us around 3 hours removing bits and getting to the seal. Within 20 minutes the new seal was in place and the process commenced of lowering the engine back on to its mountings and replacing all those bits we had removed.

Careful discipline at the removal stage (really?) meant that we had no difficulty locating or identifying the correct bolts and nuts where necessary to re-fit bits on again. Again, our main issue was that, like most maintenance tasks on boats, restricted access makes every job more time consuming and sometimes more frustrating.

As the afternoon crept on, the race against time became more noticeable.  We were doing this job in December and the light was quickly fading. Soon we had to use engine room lights and inspection lamps to see what we were doing.  An occasional bruised knuckle (accompanied by an appropriate expletive from Barry) also contributed to the frustration. This was heightened when the odd bolt fell down into the bilge and had to be retrieved from the depths of the boat. More delay!

Eventually, however, no further bits remained on the saloon sole, no bolts, nuts or washers were in evidence anywhere. The myriad of spanners and screwdrivers mingled with the block and tackle were the only evidence of the mammoth task we had undertaken.

It had taken us some 6 hours, dozens of cups of tea, lots of jokes, quite a few man-to-man anecdotes and stories to complete the job. A final cup of tea and a deep breath before we switched on the ignition to see if all ran as well as expected.

The engine roared into life and ran as smoothly as any diesel engine will at low revs. We upped the revs and everything worked well. Next, we engaged forward, then reverse gear to check the engagement with the gearbox, and made final adjustments.

Job done!

Two weeks later, we tackled the second engine. Experience led us to use a better winch but otherwise we adopted the same approach as for the first time round.

I am delighted to say that this job illustrates the camaraderie that exists within members of Walton Bridge Cruiser Club. I am grateful to Graham and Barry for their assistance and have more confidence that the job was well done than if I had had it done at a boatyard.