Category Archives: engine

LPG outboard hack 2

A short video showing how we got my Honda BF5 engine running on LPG by removing the carburettor completely and controlling speed using a needle valve.

I’m starting to wonder how many parts I could take off and still have a workable engine!

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2015-06-10 · 15:36

LPG outboard hack

I’ve been having some problems with the Honda BF5 outboard engine. Last week it failed to start at all  When Dad and I opened up the float chamber under the carburettor, it was full of white gunk.


I’m not sure what it is. It looks a lot like salt, but it is squishy and doesn’t taste like salt. We cleaned it out, cleaned the main jet with a needle, and eventually did manage to get the engine to run, but it wouldn’t idle. There’s a second path through the carburettor that’s probably the slow-running jet, and we suspected that was clogged. I took the engine to Hendy Marine at Swanwick and their engineer cleaned the carburettor in an ultrasound bath and fiddled with the engine until it ran OK. But it still wasn’t behaving properly.

This sort of thing worries me because it shows the carburettor is very sensitive to problems, and isn’t easy to fix. I don’t like things that I can’t fix myself. I’m sure I could come to be much better with engines given time, but for now it’s a problem.

Last year I thought about buying a LEHR propane outboard instead. Purportedly reliable and clean, it would also mean that I didn’t have to carry petrol on board. I personally know one person whose boat was gutted by a petrol fire, and I’m really not keen on having it around. There’s also the appeal of having a single fuel for both cooking and propulsion. LPG (propane or butane) is a lot less dangerous than petrol. On Yachting Monthly’s crash test boat they had trouble getting it to explode even when trying their best!

Then I heard that four-stroke petrol outboards could be converted to run on propane. I found suppliers of kits (mostly for generators) and there are even some DIY conversions on YouTube.

Talking to my engineer father about it, it all sounded pretty simple. And the more I thought about it, the fewer parts I thought I’d need to just get the engine running. Finally, I went outside, bodged a connection between the gas bottle and the carburettor, and got the engine to start without much trouble. I immediately did it again on video to show you all.

All that I’ve done here is rely on the gas bottle’s cooker regulator to provide a constant flow of gas into the outlet of the carburretor float chamber, so it’s squirting through the jets into the Venturi. It so happened that the gas pipe fitted over the casting. No extra hardware was required!

Of course there’s a big difference between the engine running and it being reliable and efficient. But I think all I need to achieve that is to add a regulator that is driven by the low pressure in the Venturi. One of these might do it. And I should make a proper fitting that screws into the jet inlet.

If that works I will have made a completely reversible and easy conversion. Watch this space!

Edit: I did some more research and found that a component often used to control the flow of gas into the engine is a “demand regulator” or “demand valve”. This is similar to the valve used by SCUBA divers to suck air from their tanks. This makes a lot of sense since we want the engine to suck gas from the tank in proportion to the amount of air it is drawing in, rather than squirt in a fixed flow of gas. The IMPCOGarretson KN” seems to be commonly used, and there even seem to be clones. This video shows a demand valve mounted on the side of a generator running on natural gas. This does seem to be a large component, possibly sensitive to movement.

The LEHR outboard carburettor seems to have a disc-like valve on the side as well, but it’s much smaller than the Garretson.

LEHR outboard engine carburettor

LEHR outboard engine carburettor

Edit: I checked with Calor Gas, the suppliers of the gas bottle that came with Tammy Norie and discovered that it contains 25 year-old butane not propane as I originally thought. As far as I can tell that doesn’t change things very much.


Filed under engine, Equipment, Repairs and Modifications

Engine starter fixed

When Tammy Norie’s original engine broke, I bought a second hand Honda BF5 from Seamark Nunn in Felixstowe. Unfortunately, its recoil starter broke almost immediately, stripping the teeth from the starter sprocket.


I bought a new sprocket, but that jammed during my messing around in strong winds off The Naze and I had to dismantle it and use the emergency starting cord.


I’ve been using the starting cord ever since, and the engine has been fine in all other ways. But I don’t like running it with the cover off. There’s a chance of a rope or clothing getting snagged in the flywheel.

Seamark Nunn offered to take a look at the engine under guarantee, and I finally had a chance to take the engine to them yesterday (2014-09-10). Josh, their engineer, immediately helped me diagnose the problem by pulling out a similar engine and finding a diagram from the service manual.


I thought perhaps something was bent out of shape, because my sprocket teeth didn’t engage very deeply with those on the flywheel, but Josh pointed out that my fixed cap (part 9 on the diagram) and split pin (part 7) weren’t locked together in the same way as on the other engine, and that this would mean that the sprocket wouldn’t drop out of the way of the flywheel when the engine started. That would account for the teeth getting stripped: when the engine fired up it would push very hard on the sprocket.

I looked at the other engine and noticed that I had a piece missing.


There’s a large plastic washer (part 11) that spaces out the sprocket (part 4) from the recoil assembly (part 3). I’m certain that my engine never had one of these, and I did notice some home-made plastic spacers that I found suspicious. I reckon that the original owner lost his washer and then attempted a bodge. The result is that the split pin is too low and falls out of position beneath the cap. You can see it escaping in this video.

Josh found a spare washer and a spare sprocket. We put everything together and things worked much better. I might also bend the split pin slightly to make double sure that it can’t escape.

I recommend Seamark Nunn, who have been friendly, helpful, efficient, and professional.

I also had a great chat with Josh, who is restoring a Cornish gaff ketch and has plans for a six-year circumnavigation. If he starts a blog himself I’ll link it from here. She looks lovely.

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Filed under engine, Repairs and Modifications

Windbound at Wells

Last Saturday I attempted to sail from Wells-next-the-Sea to King’s Lynn as the first step of my plan to bring Tammy Norie to Cambridge. The weather wouldn’t let me.

I left Cambridge at 06:35 carrying a sheet of 6mm exterior plywood that I planned to use for improving deck fittings, and reached Wells just after 09:00.


I bought Imray chart Y9 of the Wash, paid the harbour and dropped some money in the charity trust box as promised. I spent some time preparing Tammy and chatting to my neighbours on the pontoon — mostly motor cruisers who felt it was too rough to go out. Indeed, on my way out and over the bar I met four scurrying in, several of them ignoring the cardinal and channel buoys in their hurry to get out of the waves.

It was a bit choppy. The wind was westerly force 6 and the waves were short and high with quite a few breaking at the Wells bar. Once out past the cardinal it wasn’t too bad, but once again Tammy failed to make any progress to windward in the short sea. I made an hour-long tack northwards, trying everything I could to make progress, but when I tacked back to see how I was doing I found I’d actually slipped downwind about a quarter of a mile.

The wind was only forecast to get worse. It was clear I wasn’t going to get to King’s Lynn at all, and that it would be dangerous to have Hunstanton on the lee in such conditions. I could run back to Sea Palling and abandon my Cambridge plans, or I could scurry back in to Wells.

At this point I was a bit worried about Wells. On the way out I’d noted I had over 3m of water in the channel, and since then the tide had peaked and dropped a metre below that, so I ought to have 2m going in, if I was quick. But the tide was falling all the time and if I made a mistake I could be in quite a bit of trouble.

My main fuel tank was also running very low at this point. I’d been unable to fill up because Wells has no petrol station. So I transferred 4 litres from the reserve into the main, lifting them both into the deepest part of the cockpit to avoid getting any water in the fuel.

I was unable to raise Wells harbour on the radio or telephone, but managed to chat to the friendly guys on the beach patrol RIB who were watching the holidaymakers on the nice sheltered beach at the entrance to Wells. They suggested I come in quick.

So I did. Tammy’s 5hp engine seems just about adequate for pushing her into the wind, waves, and ebb current on the westward turn over the bar. I’m very glad I didn’t go for a smaller engine, and I kind of wished I still had the 10hp monster that I broke earlier. I’m absolutely sure that I couldn’t’ve got back in with a yuloh or scull. Engineless I would simply not have had the choice to enter Wells. Perhaps one day I won’t be on a schedule.

By the time I was at the beach chatting with the beach patrol guys over the side it was too late to get back to the town. The suggested I anchor just south of the outer harbour, and so I found a broad spot that still had some water and threw the anchor over the side. By the time I’d dropped the sail and made a log entry I was aground in a lovely spot.





I spent the afternoon trying to remove the starboard middle stanchion and trying out some kite aerial photography. At about 22:00 I floated off and rode the very strong Wells flood back to the town, where my motor-cruiser friends were chatting and helped me tie up. “You must be exhausted,” exclaimed one, and I realised that they thought I’d been out at sea for twelve hours. I explained that I’d been on a sandbank for most of the day drinking tea and playing with a kite.

I spent most of Sunday fixing the stanchion. Briefly, here is what it was like in the morning:


and in the afternoon:


It is the prototype for upgrades to all the deck fittings, ensuring they are sealed and strong. I also fixed the tiller pilot, so it was an enjoyable and productive day. Even right inside Wells the wind was very strong, and nobody was going out.

I met an excellent chap named Alan in a temporarily mastless Maurice Griffiths boat called Stella Marie who had Haslar self-stearing gear “serial number 2” hanging off the back, and we had a very nice chat about the Jester Challenge and good places to visit in the Wash. At one point he mentioned that people used to have boat stamps in the old days, and I was able to produce mine and stamp his log book, much to our mutual enjoyment.

On the whole, getting stuck in Wells was no bad thing, and I’ll make another attempt on King’s Lynn as soon as the westerlies decrease.


Filed under East Anglia 2014, engine, Logs

East Coast launch weekend, part two

This post follows on from East Coast launch weekend, part one.

After our visit to Auriga, Mum, Dad, and I sat down in the sun in Tammy Norie’s ample cockpit with tea, wine, crisps, and cake, and discussed philosophy for an hour — a favourite pastime of people on boats — before heading off for a curry with Igor and Giulia. We all went to bed reasonable early, as Auriga was due to be craned back into the water at around 07:30 the next morning.


The next morning the boat yard were quite busy moving other yachts around, and as the tide was on the ebb and there was little wind, I decided that we ought to set off early in order to get back to Suffolk Yacht Harbour in engineless Tammy Norie. Our friends had to forego their try-out in a junk rig, and we had to forego watching Auriga float again. We paddled and sailed out of Fox’s and headed back down the river.

I need not have worried. As soon as we passed under the A14 road bridge a westerly breeze appeared, and we were soon charging along on a broad reach at 5 knots. In fact, we slackened sail in order to slow down, but it didn’t help all that much. Tammy Norie seems determined to keep going no matter how I trim. I suppose it’s a feature of the Junk Rig that I’m not yet used to: there’s no flogging the sail to depower.

As we passed Pin Mill we were all gazing over and wondering about the boats moored up outside and on the shore. It was only 10:00 so we spent an hour tacking between the moorings.

One boat in particular stood out. A three-masted junk-rigged catamaran that certainly looked like a custom build. It had no obvious name, and the Junk Rig Association directory does not have a boat at Pin Mill. Do you know anything about it? Leave a comment!



We saw several other crews on their boats on moorings around Pin Mill, and waved and had short conversations as we passed. “Nice rig!” called one, and his dog barked in agreement.

Around 11:00 we turned off the wind and rand down and in to Suffolk Yacht Harbour without incident. By this time we were getting pretty good at sailing on to a pontoon.  We packed our stuff, cleaned up the boat, and had lunch at the converted lightship.

Then it was my turn to solo out to the arranged mooring and paddle back in the kayak.

Well, I made two mistakes and learned two useful lessons.

To get off the pontoon, I raised the sail while Mum and Dad hauled on the mooring lines to give me a start and get me clear of the neighbouring boats. The wind was about SE4, not entirely favourable for getting out, but I was sure I could nurse Tammy Norie out of the narrow channel with care. Unfortunately, as I was heading to the south-east edge of the entrance a massive motorboat bore down on me. Instead of standing on and asserting myself (being under sail) I bore away to get out from under, and was blown onto the mud.

Aground outside Suffolk Yacht Harbour

A friendly passing Macgregor 26 “Sara” pulled me off towards the fairway with the comment “engine trouble?”  Thank you Sara!

On reflection, I’m not sure I could’ve trusted the mobo to behave properly, and I might have caused a collision if I had asserted myself. I’d much rather suffer a little embarrassment.


Sailing out to the mooring buoy was easy. I prepped a bow line along the port side, approached it at a distance on a starboard reach, then turned up with it on the lee. I was quite pleased with myself as I reached easily over the side of the cockpit and passed my line through its loop. That was, until Tammy Norie failed to stop!

The wind, of course, was on my starboard side, and the sail on the port. Wind pressure was acting directly against Tammy turning her bow on to the buoy and coming to a stop. Oops!

Stuck on the buoy

I made off the mooring line on the port quarter and slackened the mainsheet, hoping to allow the sail to weathercock so that I could lower it. No chance. Of course, what I needed to do was gybe. The sail was mostly down, so I was able to just grab the mainsheet bundle and haul the sail over. Tammy Norie obediently swung round, the buoy slid up to the bow, and everything settled down.

Lesson: pick up buoys on the windward side!

On reflection, when making a mistake like this I should’ve just let go the mooring buoy, had a think, and come round again.

Packing up Tammy Norie took a while: sail cover, oars, horseshoe buoy, seacocks, bilge, etc. etc. I used the anchor rode to make a double sheet bend around the buoy’s loop, backed up with a Yosemite bowline, and a stopper knot on top of that, all threaded through the anchor roller. Then just to make sure I slung a loop of rode around the whole buoy, fed through the bow fairleads. I don’t think that’ll come undone.

A couple of minor things I noted as I was packing. The bagged kayak fits almost exactly into the port quarter locker along with the 50 litre emergency water and the gas bottle. Nice.


The oversized 200 litre flexible water tank (Plastimo part 16657) lies along 2m of the starboard lockers. I doubt it’ll ever be filled completely, but as it is it makes a good insulated cushion for food storage.  These bottles and jars get gently pressed against the locker top by the weight of water. I’m not sure if this will work out, but it seems pretty good.


A word about this rope. A lot of it came with the boat. It’s light and strong. And that is where its list of merits ends. It is awful to handle. It springs itself out of tightly tied coils in the locker. You can barely coil it by hand because it’s so springy. It burns your fingers if it moves at even low speed. It seems to have a life of its own and won’t stay where you put it. Nightmare rope. I’ll replace it as soon as I find some nice replacement mooring line. As it is I’m using some 8mm braided poly rigging line in preference.


Finally, I locked the boat, inflated the kayak, and left Tammy Norie behind, pausing to take this parting shot.


I hope she’ll be OK!

Postscript: At the time of writing, I’m waiting for a call about the engine repairs. Meanwhile, Tammy Norie is based at Suffolk Yacht Harbour for at least a week. The next planned trip is to Southwold and Blythburgh. Watch the blog for updates!


Filed under East Anglia 2014, engine, Logs

East Coast launch weekend, part one

The first weekend of my early summer plans was both fun and eventful. It started smoothly, then became decidedly bumpy before apparently coming to a premature end stranded in the rain with a broken engine. Then suddenly the sun came out and we were under way among Thames Barges, visiting friends, and having a wonderful time again.

I left Cambridge station late on Friday morning, carrying Eaglet, my new Sea Eagle SE330 inflatable kayak, destined to become Tammy Norie’s tender. The kayak comes in the biggest and toughest drawstring bag I’ve ever seen, with a strong and handy shoulder strap, so I was able to pack all my weekend items including my waterproofs inside, leaving just my Imray chart pack and a cup of coffee to carry. Meanwhile, Mum and Dad were driving from Chandlers Ford to Woodbridge, towing Tammy Norie from her spot in their driveway.


When I got to Woodbridge I had a chance to poke around in Andy Seedhouse’s chandlery shed, picking up a barometer, a nylon skin fitting to make a gas locker drain, a length of webbing to improve the mast lift, and a length of soft plastic pipe to reduce chafing from the yard parrel. Total cost £15. I also picked up a first aid kit, a few household drugs, and a pot of vaseline.

On my recent trip to the Baltic I found a left-over pot of vaseline on CUYC’s yacht Kestrel and it turned out to be very useful. I used it to fix the toilet pump on the first day, and to seal the bilge pump filter on the last. It makes a pretty nice non-toxic substitute for grease in the water system.

Mum and Dad arrived at about 16:30, an hour before high water, and we set about launching Tammy Norie on the slip at Robertsons Boatyard. I also arranged a couple of weeks on a swinging drying mooring at Robertsons, as I intended to make it back to Woodbridge that weekend. That didn’t happen, as you will see.

Dad and I had decided to try launching by reversing the trailer into the water, rather than hiring a crane. We thought this ought to be straightforward, though the trailer, and the brakes especially, would need cleaning afterwards to prevent salt from destroying them. The water at Woodbridge tastes saltier than the Baltic, in spite of being quite a long way upstream. And so it turned out: we just had to attach the trailer to the car on some long lines and lower it and Tammy Norie into the water until she floated off.

Here is a time lapse movie of the whole thing.

Retrieving her onto the trailer will be another matter.  Somehow we’ll need to make sure her keels are in the right position before towing out the trailer.  I have plans for this that I’ll write about later.

We made a quick shopping trip to the supermarket and got back as the tide was falling, jumped on board, and pushed off down the Deben under power into a force 3 headwind. A shame, but at least the tide was helping us along. My goal for that evening was to reach Felixstowe Ferry at least, and if we were feeling lively, even get as far as Pin Mill by the early hours. But about 30 minutes out of Woodbridge we realised that we’d forgotten to fill the little fuel tank. I had yet to calculate Tammy Norie’s fuel range, or even the most economical speed for the engine, and we felt quite insecure with only half a tank. The chart showed fuel at Waldringfield, so we grabbed a buoy there, inflated the kayak, and I went ashore with the tank in search of petrol.

I was told in the pub that the nearest petrol was miles away. Oh well, back to the kayak, back to Tammy, deflate the kayak again, and off down the river. By then it was nearly 22:00 and getting dark, so we picked up a buoy near Ramsholt and went to sleep.

By morning the wind had veered, and we were able to sail off the buoy at about 08:20 and right down the river, tacking between the boats at Felixtowe Ferry. There we saw Tammy Norie’s sister ship, Gaspar (sail number 100) on a buoy. Nobody else was sailing, though, and certainly nobody was attempting the Deben entrance. We reached the entrance at 09:30. The tide was on the ebb, and the wind was from the south, creating choppy wind-over-tide waves and not a few breakers. Time to test Tammy!

I’d previously printed the entrance guide from the excellent Deben Estuary Pilot web site and had it to hand in a plastic sleeve.


We managed to get about a quarter of the way out under sail by tacking rapidly, but it was clearly going to be a struggle, and one mistake would put us on the mud for hours in some nasty conditions, so I started the engine and we motor-sailed as far as the fairway mark.

From there we made long tacks, beating our way down the coast towards Landguard Point in the choppy swell.

It was fun for a while, and we were making progress, but in the end we got fed up and wanted to catch the Thames Barge racing and so we motor-sailed into wind until the fuel tank was empty. By that time the wind had backed enough that we could weather the point, and then everything changed. The sea levelled out, the sun came out, and we had a delightful run into the river.

We made the Shotley lock-keeper’s day interesting by sailing into the lock.  He was very helpful. Shotley, it turns out, does not have petrol either, but he said they’d have some at Suffolk Yacht Harbour. We took lunch at the Shipwreck and recovered from the morning’s bumpy ride.

After lunch we warped out of Shotley lock and caught the now south-easterly breeze north to Suffolk Yacht Harbour. After a quick pass to look in at the visitor’s berths, we sailed right in, dropping sail in seconds just inside the entrance and using our oars as paddles to get ourselves into a very sneaky position near the fuel berth.


After filling the tank with petrol we tried to start the engine, but it wasn’t co-operating. In fact, it didn’t seem to be firing at all. We tried various remedies, including Cold Start into the carburettor, and WD-40 on the high tension electrics, but it just wouldn’t respond at all. I wore the skin off the inside of a finger pulling the starter cord. We decided to take out the spark plugs to check them and to relieve any flooding.

But the spark plugs were extraordinarily stiff.  The top one was hard to remove, but the lower one didn’t seem to want to budge at all. More WD-40, and then a strong tug on the spanner, and it moved. But it also made a sickening crunch. It had broken in two, leaving the stub of the plug inside the engine block.


By now it was 19:00, we were tired, and it was starting to rain again, so we decided to pack up for the day. At this point I thought our weekend was over.

(The following track doesn’t show our tacks off Felixstowe. I think I may have switched off the tracking app on my iPhone for a while by mistake.)

The next morning I tried calling a couple of local companies, but it was Sunday and they weren’t likely to be able to do anything. The harbour master recommended we talk to Bob Spalding, a motorboat and engine company just inside the gate to the harbour. I gave them a call without result, but a bit later in the day we ran into Phil moving boats around inside their yard, and he said he’d come and take a look. We ended up taking the engine out and leaving it with him to try to fix on Monday morning. I talked to the harbour master about a swing mooring from Monday, and arranged a pontoon for that night while we waited for Phil to take a look.

Then an amazing thing happened.  We were just getting ready to move Tammy Norie along to a proper berth when I spotted a Thames Barge through the harbour entrance. Dad watched it in the distance, commented on the topsail arrangement, then said “How frustrating it all is.” At that moment, a breeze got up and the sun started to come through the clouds. I looked at the direction, thought about the tide, and made a snap decision. “Shall we go?” I said, “Let’s go!”  Mum jumped aboard and we were off into the river.

It was perfect. The barges had their mainsails reefed in order to take on groups of passengers safely, and we could literally sail rings around them. And so we did, and Dad got his close-up view of barges under sail at last. Barges like the one he’d restored as a younger man at Pin Mill. I was very pleased to have been able to get him close.

The wind and tide continued fair for a journey all the way up to Fox’s Marina at Ipswich, where my friends Igor and Giulia were restoring Auriga for an expedition to the South Atlantic. I let them know we were coming, and we drifted up there just as the wind died for the evening lull.

“I’m coming in to Fox’s with no engine,” I told Igor.

“I have to see this,” came the reply. Fortunately, he brought his camera.


Again, the junk rig made it all easy. Sailing Tammy Norie in tight space isn’t any harder than sailing the family Topper, and it’s considerably easier to drop the sail. Just as you approach the pontoon you let go the halyard, step off with a line, and you’re done. Wonderful.

Igor and Giulia came aboard for a look around.


Then we went to see Auriga.


I was curious about many things, and Igor suggested we make a tour video. You can see it on this blog under “A tour of Auriga“.

That’s quite enough for the moment. I’ll write about the remainder of the weekend in a later post.

Continued in: East Coast launch weekend, part two


Filed under East Anglia 2014, engine, Logs

Wash kit and nose plug test

We finally got hold of a wash kit for Tammy Norie’s engine. A wash kit allows the engine to be flushed through with water from a hose (cleaning out salt) and also allows the engine to be tested out of the water. This gave us an opportunity to test the nose plugs we made earlier that prevent fumes blowing back into the engine compartment and cockpit.

Thanks to Martin at Hendy Honda Marine who helped to identify the engine and found the part in a warehouse in Belgium, as well as putting together a nice spares kit.

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2014-06-30 · 19:53