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By John Williams

Beta Marine header tank problem.


After the 2023 summer of frustratingly high winds and heavy rain, the weather eventually improved to allow us to leave the berth safely, in August!


No sooner we did than we found an engine cooling problem!  Now we have had issues with weed and the filter blocking in previous years, but this was different. 


Since the engine exhaust alarm has been fitted we have been alerted at once to lack of water flow, because of a weed blockage.  But this day the exhaust temperature was a healthy 45 degrees C.  Not a salt water flow problem.  Odd sign was the strange smell from the exhaust…   So hot did the motor get, as we trickled into the berth,  that it died.  ????   Fortunately grandson Brandon was already ready with the stepping ashore line, so could act as our brakes!

We abandoned the boat in disgust  and let it cool down. Was not about to open the radiator cap!

Next day I came and checked the engine and found that we had boiled all the water and antifreeze off, in fact it had escaped into the salt water side of the heat exchanger, thus the odd antifreeze smell from the exhaust.

I had previously had  a problem with the heat exchanger, 12 years or so back.  After the annual clean of the tube stack I rebuilt all with the ‘o’ rings as supplied by Beta, only to subsequently find the ‘o’ rings leaked salt water onto the Ali header tank casting and corroded it. 


The ‘o’ rings were the wrong ones! Too skinny!  A quick repair with JB Weld and the correct ‘o’ rings and since then we had used the motor for hundreds of hours sailing (and motoring), all round the UK.

 So I set about stripping the tube stack from the header tank and yes, found more corrosion on the cast ali tank.  I could see the evidence of the repair I did 12 years back, that was OK, but near it there were other sections with signs of corrosion.


Just a little more to do, or I thought, till we get a perfect seal...


Of course to get better access to the header tank end caps I had to remove the alternator completely,  a bit of a faff. 

Alternator off.


Using a mirror on a stick, with built in LED’s, (from the middle aisle at Aldi!)   I managed to get a pretty good view of the damage. 


Clever little mirror with tiny LED's!  Can nearly see everything, or so I thought.

I set to with a couple of tubes of JB weld, and tried to gently spread it evenly in the circular opening.  It was difficult to really see well as it was applied from a funny angle   But I thought I had it cracked!


As you can see I had copious amounts of the JB weld in there, but sadly I missed a tiny section...


I devised a neat way of smoothing off the JB weld, with a hole saw wrapped in glass paper spinning in a battery drill. Made a perfectly smooth surface on the circular opening.  Though it was difficult to see, I could, whilst standing on my head in the quarter berth, get my fingers in there, to feel how smooth it was. 


Lateral thinking. Needed to make a perfectly smooth circular hole.  The sand paper and hole saw did the trick. Eventually.

Well it was not smooth enough!  After a lengthy rebuilt of the motor and another trial of the motor in the berth and we again pumped water and antifreeze out the exhaust.


To add insult to injury suddenly the starter motor then refused to work!  I thought, switch, but that tested OK.


I was at a loss as to why, so I called on Steve of Althorne Marine Services.  An ex Eventide owner and real nice chap.  Took him minutes to find the corroded connector on the solenoid and replace it, however he did tell me the main terminal on the starter was loose and that could be a bigger issue!  Did not need this!

Despondent, as the weather now in September was better than it had been all year, I got serious.  I decided to take the header tank off the motor, and the starter!  Actually to get at the starter you really had to remove the header tank as it was right above the starter making access difficult.


Some of the parts on the galley work top,  the tube stack removed showing the circular hole that has to be smooth so it seals.  A couple of the hoses that had to come off. Eventually all had to be removed..

OK soon spotted the first snag.  To remove the header tank it had to be slid to port about 6 inches, to get it off the long studs.

Not enough room!  The rear post of the engine box was in the way.  Rats. 


I thought about it then came back to base and retrieved my battery jig saw.  Once the oil empting pump and all the nearby wiring was also removed, I cut off the rear, port engine box support! Sacrilege!  Once removed I could then slide the header tank off.  I could also see the timbers that I had removed were as good as new, not bad for over 40 years in situ. 

With great trepidation I take a saw to the engine box post.

With the header tank in my workshop ashore,  I set to and stripped all down on the bench, cleaned everything and it was now easy to see where I had missed a small corroded  area on the back end of the header tank, not a big chunk missing, but enough.


I re-cleaned and sanded all the Ali at the ends and again applied JB weld.  This time it was easy to see in the ends to ensure all evenly covered.  I used the same hole saw wrapped in glass paper, a broken belt sander belt, to smooth all off until the bronze tube stack could be fitted without impinging on the case.


JB Weld, great stuff! The end caps refitted on clean 'o' rings and sealant.

New ‘o’ ring seals fitted, and a smear of heat proof silicone for good measure and all rebuilt.  Because I could get at it easily I could now  apply a vacuum to the header tank pipe fittings that proved it was water tight! Done in the time honoured way by applying a wet thumb to one side of the tank and sucking on the other so my tongue was stuck to it!  I held it on for a few minutes and it showed no sign of leaking. 

At this stage I cleaned up the three inlet ports on the header tank and the exhaust port, judicious use of a large flat file. 

The three exhaust outlets cleaned up.

Whilst I had been doing this I had  enquired from Beta about a replacement header tank, just the cast ali tank.  In case I could not restore the case...   ‘Sorry, over 30 years old and no longer available’.  A new style fabricated tank was available but my bronze tube stack would not fit, so all new parts had to be purchased to use it..  £1,000!!! Ouch.


I also asked about the starter, being a Kubota part I assumed cheap…  Wrong!  They wanted £400!  Searching the net I found one for sale for £99.00!  Ordered.

When the new starter arrived it was obviously different, a thinner body and when the old one was removed, you could see there was a different number of teeth on the pinion.  Rats again!

Then I remembered the little auto electrical place in an old shed back of an industrial unit in nearby Danbury.  A quick call and I arrived hot foot, with starter in hand.  The gent there, a real gent, picked it up, looked at the loose fitting and with a deft twist of the wrist with a pair of pliers, handed it back, ‘fixed’ he said!  Apparently these solenoids have a ‘star washer’ that is used to hold the stud in place whilst the nuts and cables are attached, it was only that star washer that was loose.

At the same time the starter motor supplier came back to me saying they did not have one to fit and I could send it back at their cost, instantly reimbursed.. A result.


I had asked Steve to assist with the rebuild, just in case, and he took just moments to refit the starter and the wiring. 

The block needed the old gaskets removing though and as he has the right tool to do that, he attacked it.

He refitted the header tank, a simple job of sliding it on the studs, but on tightening the studs there was an ominous ‘click’ and a stud wrung off, before it was even finger tight!


Can you see one stud is 1/2 inch shorter....

Rats again!

Steve nipped up to his workshop, retrieved a stud extractor and removed the offending part.

The next day I turned up at the boat  and Steve was waving a new stud at me!

It took but moments for Steve to fit the stud.  At this point I took over and paid Steve for his time and effort and refitted the header tank, exhaust, replacing all the hoses, including the ones for the anti-siphon unit that had been fitted 30 years back.  Thought it was high time for new ones.  At the same time I thought it judicious to replace the thermostat.  All new parts had been ordered from Beta, or supplied by Steve.


The 30 year old black hoses replaced with reinforced clear hose on the Anti-siphon device.  A small bore pipe leads off the device and exits over a cockpit drain as an indicator that water is flowing! It also breaks the siphon to prevent water flowing back into the exhaust and the motor...

With all reassembled I refilled the header tank with an antifreeze mix and fired the motor up.

There was instantly a leak from one of the new, clear, salt water hoses on top of the motor, leading to the blue Vetus anti-siphon fitting..  Stop motor and tighten hose.  Check all the other hoses and get a little on some of the other jubilee clips.


Restart. Motor purring and I crawl head first down the quarter berth and peer into the access hatches.  All dry!


I run the motor for 30 minutes in gear at 2000 revs, moving a bit of water round the marina!  Too hot to take cap off the header tank so home for a well earned beer.

The next day I am back. With trepidation I remove the cap, the tank is still full!  Result. No loss of water!

I run the motor for another half an hour, in gear again..  Check all the hoses and fitting again.  All dry….

I check the bilges, and sponge out a couple of cupful's that had escaped whilst I was removing hoses etc. 

I decide to glue the engine box support back in, as I appear to have won…. so a quick mix of Araldite rapid and hold the post in place.  The heat from the motor helps and within minutes it is firmly stuck.  I mix up another small batch and go round using it as filler on the two saw cuts.


Araldite Rapid.  Post back in situ.  Quarter Berth access panels to rear of motor and gearbox  replaced.

I have not painted the post, so if I ever need to remove the header tank again I have a plain mark to follow with the jigsaw!

I spend an hour or so tidying the wiring and refitting the sump pump, replacing all the engine box panels, the mast lowering gear, the boxes of engine spares and the berth cushions. 

When I am done the boat is back to normal.  The motor has also cooled down so it was safe to remove the filler cap.  Still full! Home for another  congratulatory beer!

A couple of days later, the 30th of September 2023, we were able to get away and take her out for a few hours motoring, and a little sailing.  All was good.  After returning to Bradwell we sat on board for an hour or two whilst we had a picnic and the motor again cooled.  Another check, the header tank is still full.  Fixed!

That morning we had queued for an hour in the sun for our Covid and flu inoculations’.  As we left the boat we realised our arms were really hurting, so back to base to collapse in a heap, but warm in the knowledge the boat was back in commission!