After another day in the hot, stinky bowels of the engine bay, I can report on the good, the bad and the ugly.
I'll start with the ugly, from a previous owner or fitter (or what?). The best I can say is that someone had fitted a primary filter. Its location in the port cockpit locker meant you could only inspect or service it by practicing a good deal of Boat Yoga. But, how difficult is it to find two Phillips head bolts to fix it? If you've ever tried to extract a stubborn flat-head bolt with a screw driver or impact driver, you'll know my frustration. Anyhow, its gone now.

Now, the bad.
I replaced three of my banjo bolts with Speedwell fittings, and re-fitted the fuel lines.
Using nothing but a ring spanner, I stripped the female thread on the socket at the fuel lift pump, which will need to be re-drilled and re-threaded, or fitted with a bush. There was just enough thread to replace the banjo bolt without the crush washers, but its a temporary kludge that will probably let go just when I need it most, so I've got to do something about it.
When I turned on the engine, it made a good impression of a garden sprinkler, spraying diesel everywhere.
I took off the Speedwell Fittings and replaced the old banjo bolts. It still drips, but not to the same extent.
Currently thinking about what to do next. Whatever it is, it will probably involve the complete removal of the engine.
Finally, the Good.
Successfully replaced the water intake pipe without leaks or drips. The old pipe had a length of clear drinking-water pipe which would have split or leaked at some point. However, the Bukh engine hose-end is in the most awkward place, between two engine mounts and above the engine bed, which makes it nearly impossible to reach with a spanner to tighten the hose-clamp.
I dry-fitted the removable panel that I had cut in the wall between the head (toilet) compartment and engine bay, and it sits in there nicely. Next job is to fix, glue and varnish it, and then to fit handles and locks. Its probably one of the better modifications, because I can easily get to the filter, impeller and fuel hoses without having to remove the companionway ladder and engine cowling.
I also re-routed the fuel lines into the head compartment and fitted a new Ryco primary filter. The screw-in needle vale was originally fitted directly to the tank and I might replace it with a ball-valve/stop cock (fewer joints and potential leaks). The valve and filter are now accessible without requiring Boat Yoga, and I can see what's happening with the primary filter. I also found that the drain screw in my old CAV filter is cactus, so it was time for a new filter in any case.
At some future date, I might relocate the water filter into toilet compartment as well, for ease of inspection and cleaning. However, I'd prefer to go sailing.
Before anyone asks about the photo, the door does open and close without snagging on the lines. The filter is located as high as I could get it without being above the bottom of the tank, and the fuel lines have gentle curves to get round the bends.

Now, the bad.
I replaced three of my banjo bolts with Speedwell fittings, and re-fitted the fuel lines.
Using nothing but a ring spanner, I stripped the female thread on the socket at the fuel lift pump, which will need to be re-drilled and re-threaded, or fitted with a bush. There was just enough thread to replace the banjo bolt without the crush washers, but its a temporary kludge that will probably let go just when I need it most, so I've got to do something about it.
When I turned on the engine, it made a good impression of a garden sprinkler, spraying diesel everywhere.
I took off the Speedwell Fittings and replaced the old banjo bolts. It still drips, but not to the same extent.
Currently thinking about what to do next. Whatever it is, it will probably involve the complete removal of the engine.
if i understand it right the thread to the fuel lift pump is striped,there is no good repairs other than retaping to a bsp thread and fiting a hose tail to it with a lot of sealent on the thread.the other way is to bypass the pump and fit a in line low pressure fuel pump to it ,you will have to remove the pump and blank of the pump.
Now, the bad.
I replaced three of my banjo bolts with Speedwell fittings, and re-fitted the fuel lines.
Using nothing but a ring spanner, I stripped the female thread on the socket at the fuel lift pump, which will need to be re-drilled and re-threaded, or fitted with a bush. There was just enough thread to replace the banjo bolt without the crush washers, but its a temporary kludge that will probably let go just when I need it most, so I've got to do something about it.
When I turned on the engine, it made a good impression of a garden sprinkler, spraying diesel everywhere.
I took off the Speedwell Fittings and replaced the old banjo bolts. It still drips, but not to the same extent.
Currently thinking about what to do next. Whatever it is, it will probably involve the complete removal of the engine.
I presume you can unbolt the lift pump and take it home? I would be inclined to toss the banjo bolts and buy a couple of brass hose tails and silver solder them in place or use JB Weld.
I like the filter installation. If you can just sit on your butt alongside the filter it will be a breeze to change.
Ach, my guess is that you've discovered the main source of leaking diesel as you have already picked off a few ancillary issues, so as mentioned repair/ replace the lift pump or change it out for an electric job. You could for the sake of the argument, by pass the lift pump by using a gravity tank, a fuel drum in the cockpit would suffice to test it
Happy Easter everyone! I'm a church-goer, and Easter Sunday is the most important date in the calendar for me. But, this isn't the right forum and I will respectfully refrain from engaging with any further posts on that topic. I'll keep this update to the topic of boaty-stuff.
I remain convinced that there is a cheap fix in there somewhere, but finding the parts remains a mission. After the thread in the socket for the banjo bolt on my low pressure pump, I had to find out what it was. With a borrowed gauge and a thread-testing assembly, I found that it is an M10 with a 1mm pitch thread. I would like to fix it with a Helicoil insert, which is commonly referred to as a thread repair kit on retail websites. However, it is surprisingly difficult to find a 'real' shop that supplies them, and which is open at weekends. Repco, for example, was open on Saturday, but only stocked thread repair kits for M10 with a 1.5mm pitch. Next up, I'll try Blackwoods in Hamilton, but might have to resort to on-line shopping with the mandatory several-day wait and the uncertainty that I'll get all the bits and pieces that I need, like the right drill bit, tap and tap-spanner. I'll also try the Dowty washer option mentioned previously.
I also re-fitted the cut-out to my engine access hatch, and installed a squeezy bulb on the fuel line to help push out the air when I reconnect the lines. I have a couple of sets of better-quality hose-clamps and a stop-cock coming in the post, which should help to stop a couple of minor drips in the fuel lines. I ran the engine, just to check it. It ran OK, but sounded like there was some air remaining in the fuel lines.
It took a bit of boat-yoga, but I successfully removed the cover to the low pressure pump. The photo below shows it before removal (before you ask, I had begun to unscrew the lower near-side bolt before taking the photo). As I suspected, it is an alloy casting, which is relatively soft and vulnerable to thread-stripping. Now that I have it out, I can drill and re-tap it, confident that I will not leave a metal shaving in there to do some damage to the engine's innards. I'll borrow a mate's drill-press to get it properly aligned. The photo also shows some wetness around the high-pressure fuel line, which is becoming the prime suspect in the original leak.
If I fix the leak and avoid a large bill for a new motor, I might move on to the bearings, which have probably been hammered to death, the wiring, which is a frightening rat's nest of spaghetti, and the engine beds, which have some impressive splits in the glass along the edges. Even if I get a new motor, I'd have to do something about the wiring and beds in any case.


Happy Easter everyone! I'm a church-goer, and Easter Sunday is the most important date in the calendar for me. But, this isn't the right forum and I will respectfully refrain from engaging with any further posts on that topic. I'll keep this update to the topic of boaty-stuff.
I remain convinced that there is a cheap fix in there somewhere, but finding the parts remains a mission. After the thread in the socket for the banjo bolt on my low pressure pump, I had to find out what it was. With a borrowed gauge and a thread-testing assembly, I found that it is an M10 with a 1mm pitch thread. I would like to fix it with a Helicoil insert, which is commonly referred to as a thread repair kit on retail websites. However, it is surprisingly difficult to find a 'real' shop that supplies them, and which is open at weekends. Repco, for example, was open on Saturday, but only stocked thread repair kits for M10 with a 1.5mm pitch. Next up, I'll try Blackwoods in Hamilton, but might have to resort to on-line shopping with the mandatory several-day wait and the uncertainty that I'll get all the bits and pieces that I need, like the right drill bit, tap and tap-spanner. I'll also try the Dowty washer option mentioned previously.
I also re-fitted the cut-out to my engine access hatch, and installed a squeezy bulb on the fuel line to help push out the air when I reconnect the lines. I have a couple of sets of better-quality hose-clamps and a stop-cock coming in the post, which should help to stop a couple of minor drips in the fuel lines. I ran the engine, just to check it. It ran OK, but sounded like there was some air remaining in the fuel lines.
It took a bit of boat-yoga, but I successfully removed the cover to the low pressure pump. The photo below shows it before removal (before you ask, I had begun to unscrew the lower near-side bolt before taking the photo). As I suspected, it is an alloy casting, which is relatively soft and vulnerable to thread-stripping. Now that I have it out, I can drill and re-tap it, confident that I will not leave a metal shaving in there to do some damage to the engine's innards. I'll borrow a mate's drill-press to get it properly aligned. The photo also shows some wetness around the high-pressure fuel line, which is becoming the prime suspect in the original leak.
If I fix the leak and avoid a large bill for a new motor, I might move on to the bearings, which have probably been hammered to death, the wiring, which is a frightening rat's nest of spaghetti, and the engine beds, which have some impressive splits in the glass along the edges. Even if I get a new motor, I'd have to do something about the wiring and beds in any case.


i dont think a dowdy washer will work as the thread repair is going to take up some off the seal surface .just tape it out to 1/4 bsp and fit a hose tail to it, you will need to remove pump to repair as it will have to be cleaned.
also the pressure hose looks a bit tatty and wet, its not the source of a leak?
i dont think a dowdy washer will work as the thread repair is going to take up some off the seal surface .just tape it out to 1/4 bsp and fit a hose tail to it, you will need to remove pump to repair as it will have to be cleaned.
also the pressure hose looks a bit tatty and wet, its not the source of a leak?
grich, you are probably right about the high pressure hose. However, I now have to fix the problem I made (the stripped thread in the low pressure pump) before fixing the original problem.
I'm finding it incredibly hard to find replacement parts or replacement kits. I can get a thread repair kit for M10 1mm pitch from eBay for about $24 and a 3 to 6 week wait, or I can get one tomorrow from a 'real' shop for $115. The 'real' shop has one in stock, so I'll probably just stump up and get on with the repair. I also like to talk it over with a 'real' person over the counter to make sure I do it right and have all the right bits and pieces.
I'm reluctant to drill and tap a new thread because the problems could escalate if I start to change things around.
I would have got a brass hose tail with a thread close to the pump and glued it in with JB Weld. JB Weld is about $13 and a hose tail about $8
Hi Arch
Me again again.
Your photo makes me wince!!
This is a 3 hour job.
Take the pump off. Wire brush it (with inlet and outlet sealed.)
Wash with degreaser or kerosine and then lots of soapy water.
Replace rusty bolts with stainless ones from Bunnies. Buy a spray can of red paint while you are there.
Replace bolts one at a time and try not to disturb the seals.
Repair fitting as per Ramona's post (either a straight or elbow fitting.)
Paint.
Refit pump.
Replace ratty hose.
Move on to the next job or go for a sail.
gary
Buy a spray can of red paint while you are there.
... to make it go faster?
Seriously, I have the pump off, I have the thread repair kit (as of this morning), and I'd like to get it fixed ASAP so I can go sailing.
Incidentally, the bolts are in an OK condition. The photo shows the high pressure pump behind the "ratty hose". That's where my attention will be fixed after the thread repair.
UPDATE: Successfully drilled out the hole, tapped it and fitted the Helicoil. Helped by a mate with a drill press. Needed to shorten the Helicoil, but it took 3 attempts to get it right.
Tips on Helicoil Thread Repairs;
* You can back out Helicoils after you have screwed them in, but don't do it. The reason is that if you pull and unwind it, it will likely disengage from the female thread and get itself cross-threaded.
* LIkewise, you can ease out the end and clip it off to shorten it. Same thing happens as above
* If you need to shorten a Helicoil, put one in, mark off where you need to shorten it to, take it out, clip it off or clip off another one to the same length.
* Don't try to force the old bolt into the Helicoil with a spanner, or you will strip the thread on the bolt and you will need to repair the bolt as well. (No prizes for guessing what I did)
* A good nut can be used to repair a damaged thread on a bolt, if you don't have the right die. (No prizes for guessing which die I did not have in my thread repair kit)
The engine is now re-assembled and running, but I have not solved the problem of the slow drip. I might have slowed it down, though. I now have a workaround, which is an easily accessed stop cock on the fuel line to shut off the fuel when the boat is not in use. Hopefully, this means it will not leave puddles in the bilge between sailing trips.
I am now considering my next move.
UPDATE: Successfully drilled out the hole, tapped it and fitted the Helicoil. Helped by a mate with a drill press. Needed to shorten the Helicoil, but it took 3 attempts to get it right.
Tips on Helicoil Thread Repairs;
* You can back out Helicoils after you have screwed them in, but don't do it. The reason is that if you pull and unwind it, it will likely disengage from the female thread and get itself cross-threaded.
* LIkewise, you can ease out the end and clip it off to shorten it. Same thing happens as above
* If you need to shorten a Helicoil, put one in, mark off where you need to shorten it to, take it out, clip it off or clip off another one to the same length.
* Don't try to force the old bolt into the Helicoil with a spanner, or you will strip the thread on the bolt and you will need to repair the bolt as well. (No prizes for guessing what I did)
* A good nut can be used to repair a damaged thread on a bolt, if you don't have the right die. (No prizes for guessing which die I did not have in my thread repair kit)
The engine is now re-assembled and running, but I have not solved the problem of the slow drip. I might have slowed it down, though. I now have a workaround, which is an easily accessed stop cock on the fuel line to shut off the fuel when the boat is not in use. Hopefully, this means it will not leave puddles in the bilge between sailing trips.
I am now considering my next move.
I feel for you, I've been down the garden path to solve mechanical issues before, a process of elimination ensures all bases are covered, it does seem like heavy handed botchy techniques have been employed, good on you for persisting. And via your post most of us learn something
Bukh engines may be painted red for a reason such as a warning. Seems there are more Bukh engine owners here with problems than any other.
Julesmoto has just posted problems with his Bukh. ![]()
Bukh engines may be painted red for a reason such as a warning. Seems there are more Bukh engine owners here with problems than any other.
Julesmoto has just posted problems with his Bukh. ![]()
This sort of fuel leak problem is pretty universal for all motors with threads. JB Weld costs about $13.
Some further information ...
A quick review of receipts shows I have spent about $400 on tools and about the same again on parts. The next round will definitely cost more, but but its good to know I've pushed the "cheap fix" as far as I can. I've also learned a good deal from the experience and have done some necessary surgery on routing the fuel lines, cutting panels and other bits and pieces.
Got a diesel mechanic to take a look. He thinks there may be a leak in the O ring in the high pressure pump. It might be a quick fix (take off and replace) or a slow fix (disturb the calibration and have to recalibrate), but we will not know which one until we take it apart. The risk of having no working engine while we sort it out is a little too far for me, so I will not attempt it on my own. The mechanic also pointed out that the bearings were cactus (as I suspected). The cracks in the engine beds will need the attention of a Shipwright - they may or may not be serious. If they are serious, they can only be addressed when the engine is pulled out. The exhaust hoses are also looking old (brittle) and are not properly routed through to the stern. Replacement of the exhaust gear will need a very small person with very long arms, or removal of the engine. All this points to a complete removal of the engine. The wiring works, but is horrible.
PS I know the diesel mechanic makes a living from selling new engines, as well as servicing them, but I respect his assessment of my old engine.
PPS The engine is the original that came with the boat in 1985. No matter what I do with it, it will still be an old engine
PPPS I have some JB Weld, but don't like the thought of gluing stuff together when it should be bolted. At some point you will need to take it apart again, and the JB Weld might give you no option but to break it, and then you might as well say goodbye to the whole engine.
I had a small fuel leak on my Buhk 10 hp. I had taken the injector out for a clean and new tip. When I put it back I over tightened it slightly and deformed the sealing ring. I got a replacement ring and from then on as I tightened the injector I rotated it back and forth to sort of ' lap it in '
It worked for me but showed how critical getting it right is.
PPPS I have some JB Weld, but don't like the thought of gluing stuff together when it should be bolted. At some point you will need to take it apart again, and the JB Weld might give you no option but to break it, and then you might as well say goodbye to the whole engine.
I was suggesting JB Weld for the thread problem. JB Weld comes apart with heat like any other epoxy.