The Part Cost Twenty-Odd Pounds. Fitting It Nearly Cost Us July.
The Part Cost Twenty-Odd Pounds. Fitting It Nearly Cost Us July. The Bolts Were Right There, Tucked Against the Engine Mount. Nothing Aboard Could Turn Them.
July 2, 2026 · 9 min read
The plan for July was Yarmouth, then west. One pump bolt had other ideas.
There is a law of sailing that every owner of an auxiliary diesel learns sooner or later. The bolt that matters is always the one you can see and cannot turn. And on a small marine diesel, it is always down against an engine mount, in a box the builder never meant a grown man to reach into.
I am not a marine engineer and I am not selling anything. I am sixty-eight, I spent my working life as a draughtsman, and I have kept a Westerly Fulmar at Swanwick for eleven years. The previous owner repowered her with a Volvo MD2020, which I was told was a blessing. Most of the year it is.
I am writing this for every owner who has ever lifted the companionway steps, looked down at the back of the engine, and felt that particular drop in the stomach. Because an old engineer two berths down handed me the answer, and he asked me to pass it on.
Why those bolts are where they are, in plain English
When the yard dropped the engine into the boat, they fitted it into a sealed box under the companionway steps, with sole boards on one side and a calorifier on the other. To make it all fit, the raw water pump went low on the engine, and the two inboard mounting bolts screw in from behind, pointing straight at the engine mount. On the drawing board in Gothenburg, there is room. On your knees at a berth, head down in the box with a torch in your teeth, there is not.
The bolts are not the problem. The bolts are just steel, and mine were not even stiff. The problem is the geometry of every tool that will physically fit into that gap. There is room to get a spanner on. There is no room to swing it.
Everything in my toolbag went into that box. Here is what each one did.
- Half-inch ratchet. The handle met the engine bearer before the socket ever seated.
- Stubby spanner. A few degrees of swing at a time, flip the spanner, take another few degrees. I worked it out at something like three hundred flips of a flat spanner, in a space I could not see into.
- Flex-head ratchet. Bent in past the pump, seated, then folded the moment I leaned on it, and I left skin from two knuckles on a jubilee clip.
- Universal joint on an extension. Deflected sideways and walked the socket off the bolt head every single time.
- Wobble socket. All angle, no torque. Exactly backwards from what that bolt needed.
The engineer: ninety-three pounds an hour, and he could not come for weeks
Here is the part nobody puts in the brochure when you buy the boat. A marine engineer on our coast starts at ninety-three pounds an hour with a minimum of one hour, and all travel time is chargeable, both ways. Out of hours there are call-out fees of two hundred and fifty pounds before anyone steps aboard. And that is if you can get one. The good ones are booked for weeks in season. A friend of mine describes them as being like rocking horse droppings, and he is not wrong. Another chap at our club was quoted seven hours of labour for a routine engine service, mostly because of what the engine sits behind.
So there I sat in the cockpit at six in the evening, grease to both elbows, a pump I could not get off the engine, and a passage crew expecting to leave for the West Country inside a fortnight. Margaret came up the pontoon with a flask and looked at my face and did not ask how it was going. She has crewed for me for thirty years. She just said, we will sort it. She always means it.
Steps out, sole board up, head down in the box. A bolt I could touch and could not swing at.
Then the old engineer two berths down wandered over
Les keeps a Moody two berths along from us. Seventy-four now. He spent thirty years as a marine engineer in yards up and down the Solent before he retired, and I had seen him that spring at the Beaulieu Boatjumble, going through a crate of old spanners the way other men go through boxes of records. He came down the pontoon the next morning, listened to me describe the pump for about a minute, and nodded the way old hands nod at a story they have heard two hundred times.
He came back from his boat with a slim flat steel bar, about fourteen inches long, a square drive at each end, a fixed offset in the middle. He had me press my thumb inside the drive end. Something moved. A roller chain, running the length of a sealed steel housing.
"The chain takes the bend for you."
The body holds its shape and the chain carries the turn dead square to the socket, whatever angle you are working at. Les told me he has had pumps, alternator brackets and heat exchanger fittings off more auxiliary diesels than he can count with a bar like it, and never once lifted an engine off its mounts to do it.
The sealed chain is the trick
A roller chain inside the steel body carries the turn around the offset, so it never folds like a flex-head or walks off like a universal joint.
Slides into the blind gap
A slim flat bar goes in between the pump and the engine mount where no spanner in Britain can swing.
Your own sockets
Square drive at both ends takes the sockets and ratchet already in your toolbag. No proprietary anything.
It reaches. It is honest.
Rated to seventy newton metres, a hair past fifty foot pounds, which is a proper pull on a pump bolt. It solves access. It is not a miracle for a stud corroded to nothing.
It only comes from one place
You will not find it in a chandlery, and you will not find the real one on Amazon. The maker sells direct from their own site only, and it comes to your door, tracked, for sixty-nine pounds. That is less than one hour of a marine engineer once the travel is on the bill, for the tool that turns the job that strands you into twenty minutes at your own berth.
What happened next
Other owners who stopped paying for access
"Did the whole raw water pump job at the berth for the first time in eleven years of owning the boat. The bolts that used to take me an afternoon came off in two pulls each. I sat back on the steps and laughed."
"The two inboard pump bolts. Every MD2020 owner knows exactly which two I mean. Off in minutes, socket square the whole time, engine mount never touched."
"Bought a cheap copy off eBay first. It folded behind the engine just like my flex-head. The real one with the chain in it does not fold. Night and day."
Les learned the trick over thirty years in Solent engine bays. Now he keeps a count, and he passes it on.
Get yours before your next passage
If you sail with an auxiliary diesel, and you have ever knelt at the companionway with one arm in past the elbow, looking at a bolt you could see and could not turn while your weather window closed, you already know exactly what this is worth. When it comes to that pump, even a well-kept boat is a complete pig. This is the tool that changes that.
Under Sail Field Notes is a reader-supported publication. This is a first-person account from a yacht owner and reflects his personal experience. The Savary offset extension wrench is a hand tool designed to reach fasteners in tight, blind locations. It improves access to a bolt; it is not represented as a remedy for fasteners that are corroded or seized beyond normal service, and it will not rescue a rounded head. Always follow proper service procedures and torque settings. Results vary by vessel and condition.
