Practical Boat Owner – June 2019

We were in Roscoff getting

ready to fill up with diesel fuel;

the tank was about quarter

full in our 36ft Najad. I cleared

the decks around the filler

and placed the funnel in the

neck of the filler. I was just

about to pour in some diesel

bug additive when to my

horror the little plastic sealing

cap from the diesel bug bottle

fluttered into the funnel and

down the fuel pipe!

I had disastrous visions of

this little plastic disc floating

around the tank then one day

blocking the feed pipe to the

engine at an inopportune

moment.

A kind bystander went to

the marina office to contact

the local engineer only to be

told that he was off for lunch

(at 1100) and was not sure

when or if he would be back!

So it was up to us to sort it

out. The flexible filler pipe

descends about 1.2m

vertically and was then jubilee

clipped to a right angled

stainless steel pipe welded to

the fuel tank. The obvious

thing was to disconnect the

two, having checked they

were joined above the level of

the fuel, but after an initial

attempt it became evident

that further manipulation was

very likely to break the

welded joint.

Plan B was to try and fish it

out from the top but a 1.2m

Vacuum to the rescue

Debris down the pipe! Simon James

saves the day with suction

4WD for the dinghy

came off, showing the piston,
stuck fast at the top of its travel,
with rusty, oily liquid as the
red-handed culprit.
I sprayed in some
penetrating oil and left it to do
its job, returning every evening
for a week to add more.
A sharp tap with a softwood
punch and a hammer moved
the piston a few millimetres.
Not wanting to force things, I
added more penetrating oil
and left it to do its work for
another 24 hours, before
returning. A few more days in
this vein and, eventually, with
the encouragement of a large
screwdriver used as a lever on
the flywheel, the piston moved
its full travel from top to bottom
and back again. The engine
was unseized!
On these engines the
cylinder is cooled with salt
water pumped around the
outside – simple, but it does
risk some corrosion – and the
large quantity of white salt
deposits and corrosion paid
testament to the fact that
maybe I hadn’t been as
fastidious as I should have
been about flushing through
with fresh water after each use.
Nonetheless, the metal
looked in a reasonable state,
so I poured in some white
vinegar. Next morning, the
deposits had all but vanished

• dissolved by the vinegar
  acid. A scrape with a softwood
  lolly stick and a quick go with a
  vacuum cleaner left things
  looking much improved – the
  waterway was clear for the first
  time in a while!
  I poured in some more
  vinegar for the sake of clearing
  out any remaining deposits.
  Before reassembly I ordered
  a new cylinder head gasket
  from ebay for the princely sum
  of £8. A useful tip is that these
  engines were also badged as
  a Yamaha 2hp, so spares are
  interchangeable.
  Before refitting the cylinder
  head, I ensured both mating
  surfaces were scrupulously
  clean by using fine sandpaper
  on a flat surface and flatting
  back both engine block and
  cylinder head. This done, it
  was a quick job to reassemble.
  With a slug of fresh fuel in the
  tank, it roared (well, maybe
  groaned is more appropriate
  for such an old engine) into life.

Old age demanded

improved means of moving

the dinghy from the rack to

the slipway. First a pair of

wheels from an old

launching trolley were fitted

to the keel. I used a 10mm

threaded bar, but the

wheels had a 12mm bore.

Heatshrink tubing was

shrunk onto the bar in three

layers to provide a smooth

bearing. To lift the bow, I

modified an old golf trolley

that cost £3 from the local

recycling centre. Job done!

pipe was way beyond any

grabber that we had.

So onto plan C –

desperate measures. Out

came a 15mm dia plastic

pipe, a vacuum cleaner and

enough rags to seal the

plastic pipe to the vacuum

cleaner suction pipe. The

plastic pipe was inserted

into the filler pipe down to

the elbow and a couple of

minutes later I was able to

very carefully lift the disc out

to applause from the

growing audience.

James Brooking’s wheels idea

The disc inside the lid of

the fuel additive bottle

flicked straight into the

fuel funnel

The vacuum cleaner was

connected to a small bore

plastic pipe which was fed

down the fuel pipe

WARNING: do

not attempt

near petrol

fumes!

Fuel

tank

Welded stainless

steel elbow at the

back of the galley

Disc dropped as

far as this elbow

Fuel level

Filler

Jubilee clip

Jubilee

clip

Flexible

filler pipe

1.

2 m

Simon James’s Najad 360

Dolphy 8

C

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