Had a bad experience today in F5

[TonyS]

We were sailing along, 20 kts of wind behind, through Les Sept Isles, when we tried running the engine for 20 mins to see if we could reach St Peter Port.
Suddenly the engine died as if running out of fuel. We anchored of Perros (first time under sail) and a friend helped us to the marina where we were towed in. The water bleed at the bottom of the primary filter when opened doesn't show anything except bubbles of air are sucked in. I have taken the the hose from the tank off the filter (the one that goes through a shut off valve) I cannot blow through it from either end.
Any suggestions as what to do please. Standard 2003 Bavaria pipework with connections to top of tank.
Tank is half full and fuel seems clean.
Engine will run for 5 mins but increasing revs and it stops.

 

[sarabande]

is there suction lock ? Have you checked the breather pipe is clear ?

 

[Heckler]

We were sailing along, 20 kts of wind behind, through Les Sept Isles, when we tried running the engine for 20 mins to see if we could reach St Peter Port.
Suddenly the engine died as if running out of fuel. We anchored of Perros (first time under sail) and a friend helped us to the marina where we were towed in. The water bleed at the bottom of the primary filter when opened doesn't show anything except bubbles of air are sucked in. I have taken the the hose from the tank off the filter (the one that goes through a shut off valve) I cannot blow through it from either end.
Any suggestions as what to do please. Standard 2003 Bavaria pipework with connections to top of tank.
Tank is half full and fuel seems clean.
Engine will run for 5 mins but increasing revs and it stops.

Blow down the tube towards the tank, there is a small gauze filter usually, on the end of the stack pipe, this can get blocked and cause the symptoms you describe. You should be able to blow any cack off, it is probably the bug, need to get some marine 16 in there pdq.
Stu

 

[Ex-SolentBoy]

Different engine, but we had a similar problem.

I would change both fuel filters first before doing anything else.

 

[TonyS]

Blow down the tube towards the tank, there is a small gauze filter usually, on the end of the stack pipe, this can get blocked and cause the symptoms you describe. You should be able to blow any cack off, it is probably the bug, need to get some marine 16 in there pdq.
Stu

I have tried blowing but nothing seems to happen. Will have another look tomorrow at the elbow connector into the tank. It is just nylon.
I put marine 16 in earlier but the fuel and water trap seem clean.
The shut off valve is a possibility but it has steel pipes at either side and the fuel hoses are crimped onto this but behind the bulkhead where they are inaccesible.

 

[TonyS]

is there suction lock ? Have you checked the breather pipe is clear ?

I have taken off the filler cap and that makes no difference. There must be a suction lock as when the water valve at the bottom of the filter is opened air is sucked in. Also when the pipe to the filter from the tank is removed, no fuel comes out.

 

[TonyS]

Different engine, but we had a similar problem.

I would change both fuel filters first before doing anything else.

I could do that but why is air sucked in from the water bleed hole if the filters are blocked. My reasoning is that there must be a blockage and it must be before the filters. Perhaps in the shut off valve. I will see what I can access tomorrow.

 

[Talulah]

I could do that but why is air sucked in from the water bleed hole if the filters are blocked. My reasoning is that there must be a blockage and it must be before the filters. Perhaps in the shut off valve. I will see what I can access tomorrow.

I too would try first just by swapping filters. Wouldn't change the engine filter, just the pre-filter.
If you haven't got a spare filter you could see what happens without one.
Wouldn't be surprised if it was the filter even though air will suck in from the bleed screw when opened.

 

[rbcoomer]

Does the engine run if you remove the fuel filler cap?

Seems an oddball question, but a friend of mine encountered exactly the same symptoms on an Arriva sportsboat. Having gone through the pain of filters, tank clean & fresh fuel, they eventually discovered a recent looking weld on the fuel tank breather. Upon removing hose and trying to blown down it, they discovered it had effectively been welded shut - resulting in a vacuum in the tank! Although unlikely, a blocked breather is easy to check and could save you hours!

 

[TonyS]

Does the engine run if you remove the fuel filler cap?

Seems an oddball question, but a friend of mine encountered exactly the same symptoms on an Arriva sportsboat. Having gone through the pain of filters, tank clean & fresh fuel, they eventually discovered a recent looking weld on the fuel tank breather. Upon removing hose and trying to blown down it, they discovered it had effectively been welded shut - resulting in a vacuum in the tank! Although unlikely, a blocked breather is easy to check and could save you hours!

It runs for 5 mins at low revs then runs out of fuel creating a vacuum in the filter. It has done a couple of hundred hours in the last 8 weeks down to Ile d'Yeu and back. The only thing today was being thrown about as we left Trebeurden into a F5 before we turned the corner 30 mins later. But we were sailing then!

 

[rbcoomer]

It runs for 5 mins at low revs then runs out of fuel creating a vacuum in the filter. It has done a couple of hundred hours in the last 8 weeks down to Ile d'Yeu and back. The only thing today was being thrown about as we left Trebeurden into a F5 before we turned the corner 30 mins later. But we were sailing then!

My friends experience was similar - he'd had the boat a year and done some quite long runs, but the poor welded repair had reduced the diameter of the breather. Whether a corrosion build up, cobweb or whatever - the continual draw of air had resulted in a blockage at the restriction. After 20 minutes or so, the engine could be restarted as the vacuum had slowly released! Removal of filler cap would prevent a vacuum build up. I'm assuming engine is diesel? Don't run without filler cap on a petrol as petrol vapor sinks and you don't want it in the boat! If petrol, wait until engine stalls, turn off and the open filler cap - if you hear a sharp hiss of air being drawn in then the breather is likely ineffective or blocked.

The time you were 'thrown about' is also quite likely to have stirred up sediment in the tank and perhaps partly clogged the fuel pick up or filter? Blowing down a pipe might also not be enough - perhaps a bicycle pump would work better to check through? Could something have been dislodged and damaged fuel/breather pipes perhaps?

The vacuum creating the air draw when you open the bleed screw is because the pump has been 'sucking' the pipes, but there has to be air somewhere to create the vacuum and if the pipes are full of fuel (they must be for engine to run in the first instance), then this must be in the tank, filter or water separator. (A long time since I did physics at school, but I don't think you can create a vacuum in liquid! ) Same vacuum that pulls in air to create the bubbles will stall the engine if strong enough.

 

[Seadog17]

I haven't read the whole thread but, it could be a collapsed pipe on the suction side. Check if any of the lines to the pump are soft/spongy. If air is going in when you open the bleed then that in my mind is the most likely cause. Dirt in the tank, very unlikely to cause a blockage, unless chronic.

 

[Seajet]

It does sound like a blocked breather to me.

One trick I discovered when the inlet holes on my saildrive were clogged with fine weed was to carefully take off the inlet pipe at the top and blow down it with the dinghy pump.

 

[lenseman]

You really know where the problem is located as you have done all the correct tests?

You say that when you loosen the filter bleed screw, "air is sucked in". this is because the engine lift pump has sucked and sucked until it can suck no more leaving a very good vacuum and opening the bleed just allows air into the system.

You say you cannot blow (or suck) from or to the tank via the shut off valve. This is because it is blocked and I am not talking partially, but totally blocked!

I think you said you have loosened the fuel inlet cap on deck and you still have to problem, so it cannot be anything else than a blocked pipe twixt tank and filter and that includes the shut off valve!

You will need to disconnect at one or possibly both sides of the shut off valve and/or possibly replace this valve if it proves that this is the fault. Otherwise it is just a blocked pipe.

 

[lw395]

A mate of mine had a very similar experience.
Traced to a fuel shut off valve with a lever handle that vibrated shut when the boat slammed in waves.

 

[ribrage]

We were sailing along, 20 kts of wind behind, through Les Sept Isles, when we tried running the engine for 20 mins to see if we could reach St Peter Port.
Suddenly the engine died as if running out of fuel. We anchored of Perros (first time under sail) and a friend helped us to the marina where we were towed in. The water bleed at the bottom of the primary filter when opened doesn't show anything except bubbles of air are sucked in. I have taken the the hose from the tank off the filter (the one that goes through a shut off valve) I cannot blow through it from either end.
Any suggestions as what to do please. Standard 2003 Bavaria pipework with connections to top of tank.
Tank is half full and fuel seems clean.
Engine will run for 5 mins but increasing revs and it stops.

What boat and what engine ?

I towed in a yacht a few years ago bavaria or such with a similar problem it had an electrical anti syphon valve on top of the tank as the outlet of the tank was above the engine and the fuel tank by the companion way stairs.

the electrical supply was lost and the valve closed off the fuel from the tank , hence the lift pump sucked like crazy built up a a vaccum and the engine slowly died , we took the innards of the valve apart (simple plunger) and bled the system and sent him on his way

If no valve:

other thought , get your dinghy pump and connect it to the pipe from the tank and try blowing down the pipe using the dinghy pump see if it clears the blockage , if not try replacing the pipe as they are twin core with an internal weave for strength, while the pipe is off push a coat hanger into the tank outlet

or try running the engine from a seperate fuel source ..ie a jerry can with a hose from it, just to get home or to test the theory

my moneys on the electrical anti syphon valve on top the tank if its fitted , the supply is from the ignition switch , cant recall if there was a fuse ...good luck

 

[TonyS]

Sucessfully resolved with all your help. One question

You really know where the problem is located as you have done all the correct tests?

You say that when you loosen the filter bleed screw, "air is sucked in". this is because the engine lift pump has sucked and sucked until it can suck no more leaving a very good vacuum and opening the bleed just allows air into the system.

You say you cannot blow (or suck) from or to the tank via the shut off valve. This is because it is blocked and I am not talking partially, but totally blocked!

I think you said you have loosened the fuel inlet cap on deck and you still have to problem, so it cannot be anything else than a blocked pipe twixt tank and filter and that includes the shut off valve!

You will need to disconnect at one or possibly both sides of the shut off valve and/or possibly replace this valve if it proves that this is the fault. Otherwise it is just a blocked pipe.

Hi,
Thanks to everyone for their help.
This morning for the third time in 24 hrs we removed everything from the rear cabin (our store room). I then found a cycle tube with a car type valve and cut the valve out around the base. I rigged this to the electric cycle pump. I again removed the connection to the filter by holding one 17 mm spanner on the crimp and undoing the nut. I turned on the pump and put the valve base with its small hole against the end fitting of the pipe. Suddenly it ran free. I cleaned it off and again tried blowing through. It needed no pressure and bubbles were heard in the tank. I put the pipe back in the filter and restarted the engine. Despite no fuel in the intake it quickly purged the air and has now run at cruising power for 30 mins.
I will now replace the engine fuel filter in case anything got through. I also propose to buy a length of fuel hose so I can connect the tank and engine filter directly, in case it happens again and I need to do something at sea ( working under the rear bunk with limited access is not easy).
A question though. I have now removed the pipe from the filter by holding the crimp a few times. In other words the fitting has been turning in the rubber pipe despite the crimp pressure. It does not leak now but would it be better to carefully cut off the metal crimp and replace it with a jubilee clip. Crimps make working on the pipework very difficult.

One interesting thing is that we are indebted to a German yacht who had listened to our conversations with another British yacht that left a few minutes after us and which eventually towed us the last few hundred meters to the marina entrance. The Germans gave us the Perros opening times and a phone number to call. Times are very restricted but it is a lovely marina and has lots of visitor space and the capitainery were able to talk to us in English and arrange the final tow in by a real expert boatman.

 

[Playtime]

Hi Tony

This could well be a known problem - the Bavaria fuel shut-off valve is undersized and tends to block at inconvenient moments.

Take a look at this thread

 

[TonyS]

Hi Tony

This could well be a known problem - the Bavaria fuel shut-off valve is undersized and tends to block at inconvenient moments.

Take a look at this thread

Hi Roger,
Thanks for that. It is a pity he didn't say the size to drill. I couldn't work out yesterday how to take the fuel shut off out. Have you done yours?
Where are you this wet and windy summer? We haven't seen anyone from the BOA down here. We are now getting gusts of 25 kts but it is quite sheltered and the best part, it is warm and sunny.

 

[Playtime]

Hi Roger,
Thanks for that. It is a pity he didn't say the size to drill. I couldn't work out yesterday how to take the fuel shut off out. Have you done yours?
Where are you this wet and windy summer? We haven't seen anyone from the BOA down here. We are now getting gusts of 25 kts but it is quite sheltered and the best part, it is warm and sunny.

Hi Tony

I think mine may be different to yours as it's on the end of the bed and has compression joints either side that can be undone normally. They are actually hidden by the rubber mountings but these can be removed first.

I haven't modified mine as I've had no problems. I also use Marine 16 as a matter of course.

We're just back from France - will send a PM with more details.