If I can manage to get hold of a portable unleaded pump I can manipulate the air dock the boat is on to be nose down and leaning to the right (the side of the filler that will be used by the spear) and in theory the object the dragged down on that side through the baffle corner cut outs and straight to the spear. In theory.... thanks for asking that question it opens another option to try....
I'm not convinced it's not something as simple as the breather yet.
For what it's worth my breather salting up was on the breather mesh caused by the dreaded sharkcat mist and the breathers were mounted up on the sides of the cuddycab. The mist simply sucked into the mesh and sort of built up... sometimes.
As you probably know that mist is highly unpredictable.
Have you ever tried it with the filler cap off or are the breathers just an open hole with no mesh at all???
Convince me
If you eventually go with the spear I'd hook a garden hose to the tank pickup tube and blast water in there to help flush the crap from the back to the front.
Have to add I'd have a slight concern about air dock rollover by tilting, you'd never live it down. Jeez that would be embarrassing.
Im pretty confident its not the breather, we have run it with the cap off and it hasnt fixed it. Im not too concerned about tossing the airdock, that stuff happens to other people, but I will now lash it to my pontoon now that i have opened my big mouth
One thing you can do to create a cheap vacuum that should be easy enough to manipulate to the far end of the tank. I can't guarantee how safe it is with fuel, If you filled the tank with water its perfectly safe. this is all assuming you have an air compressor. below is a cheap ejector type vacuum.
Get a length clear plastic hose (20mm) long enough reach the bottom of the tank, and to point somewhere you want the water or fuel to end up. A cheap compressed air blower with the long nozzle. Poke the nozzle into the hose in the direction you want it to flow, fire up the compressor and you have a cheap vacuum that can be poked just about anywhere. If the object is to large to be pulled through the hose, continue blowing air through the hose and remove it from the tank. I have used this method to successfully remove washers and crap from an 80L tank. Although I could shake the tank around.
Next time fuel bulb id sucked flat prove the issue is the tank by cutting hole in fuel line on tank side and see if the bulb recovers shape? If it doesn't it is at the bulb. I know you have replaced the bulb but.... Does it only happen at higher rev range? Is your fuel bulb mounted vertically or horizontally?
Unfinished sharp ends on stainless feed pipe exiting the tank can delaminate the fuel hose where it attaches to the tank. That took us a while to work out as at random times teh delaminated hose would act as a flap valve . We did it a couple of times with new hose and the nitrile lined stuff did it. Cleaned up hose tube edge and problem gone.
just a few more dumb thoughts.
I'd be buying a ebay $30 10m 12mm endoscope and draining tank and going for a fish with it attached to one of those cheap $10 sewer clearing springs . Just need to test the camera in some petrol / fumes for 20 minutes somewhere safe first as it may dissolve or lens may cloud straight over or insulation degrade. At your own risk of course.
You can rent pro borescopes as this company has supplied thermal cameras to a business I know in the past, (07) 3717 9100 http://www.techrentals.com.au
The trouble is comorant that the crap is in the back of the tank and the pickup is at the back of the tank but exits at the front of the tank. The only feasible access hole is the filler hole also at the front of the tank.
Problem, there's baffles in the tank and at this stage an unknown quantity and configuration. Hoping the corners of the baffles are cut out to allow the crap to flow from the back to the front.
I'm convinced ShaneIm pretty confident its not the breather, we have run it with the cap off and it hasnt fixed it.
Now, as said above, find a way to prove the crap isn't collecting between the outlet exit from the tank & the primer bulb.
It's doubtful to be anywhere else other than in the tank but it would be nice to prove it before getting started eh?
Pickup-->hose-->metal line-->hose-->primer-->filter-->motor?
Can the tank maker provide any baffle info?
Final thought, it would be nice to catch the crap in a sieve just to know you found something.
I had a lot of trouble with my system because the internal size of the fittings were to narrow it would be fine for a while then it would lose pressure and would have trouble pumping up after we made them bigger it was fine.But it sounds like something in the tank.
I just happened to run across a post on The Hull Truth with guys reporting the same problems, irregular sealing of the supply form tyne tank.
Seems that they all had knowingly lost the small coated paper seals from the top of fuel additive bottles into the tank (by mistake or just dumb luck). I was surprised how many guys posted in having encountered this problem over the years...
Some encountered the supply dramas you are having intermittently in the way you are, others never did have the problem after many years of use. Some fished them out, with GREAT difficulty.
Effect ion any given tank appears to depends on the configuration of the pickup, whether they use of an extended mesh gauze strainer etc or similar.
It does seem to support the theory of something floating about in the tank as the likely cause.
Can you get to the section of tank directly over the top of the pick up inlet for direct visual of that chamber as well as the pick up itself. maybe put in an inspection opening (with screw in stainless cap to seal up) to close it off?
Im at Plan T now. With everything stated in mind I came up with this today. I wanted to get the fuel out of the tank so I got hold of an external fuel pump that they use to replace buggered pumps on race cars etc. Got a 10mm piece of pipe down the filler and pumped out the 170 litres that was in the tank by getting the boat in a bow down, starboard leaning attitude (you are right Fed, I lashed everything up so it could not topple but it was horrible to be standing on and got attention from the poor neighbours). So we are now bone dry empty, there is maybe 2mm on the dipstick in her front down attitude and nothing as soon as you start to lift the bow, so at max maybe a couple of litres left. I am trying to source a trash pump or fire pump now with an inlet less than 50mm (the filler diameter) and I am going to fill with water through the tank pick up to get things moving and draw it out through the filler with a pump capable of getting it out quick. With the boat back in her precarious angle, the object has to move through the corner cut outs of the baffles towards the front to a big sucky thing which I will pump into my 800 litre ice box lined with thick plastic. If the bin fills I will drain it and go again. When (hopefully) I see the culprit in the box, I will do a little dance, crack a rum can and ceremoniously dispose the object to the shithouse. Then I can wrap up the liner, dispose of it responsibly if there is sludge in it, then get on with life. Am I missing anything? Thanks to Lance for chipping in on my plan. If anyone has or knows someone with a pump that can do the job, there is money/ beer/my sister in it for you.....
Grab a swimming pool pump.
Hi Fed . Tank builder will have done greater than 40m cut outs in baffles so it should be able to work. You would be amazed with a bit of time where you can push a 8mm camera on a bent bit of flexible push cable ( twisting it to walk it into holes) . We have saved hundreds of thousands in non destructive membrane repairs in buildings by being able to discover and diagnose the exact failure points and also confirm the structure rather than have a bunch of knobs tear it all apart at our expense rather than the original warranty. Even the cheap nasty ebay ones are waterproof and give great colour pictures with led lighting. I am all for trying anything non destructive these days and if the tank is empty and blow air through it to get rid of the last bits or pour as a flush a bit of kero or diesel that doesn't fume / explosive vapour the same way and it become pretty low risk. The cheap nasty ones just plug into a USB port on your laptop like a webcam
Have pulled half a dozen tanks out of old boats and always amazes me the stuff in them or reason they fail but a new tank has me a bit mystified unless it is rag or such.
Hey mate I've got a spare pump with filter for a blow up pool in the shed if you want it.
Of course I want it mate. I will text ya and see if you are up
My mate who is heaps smarterer than me said the same thing Fed. I dont want to go drilling into the tank so yours and his idea with the pool pump is the way forward
Any feasible plan is better to try before resorting to 'destructive' means.
Is the filler cap through the coaming/side deck? Can't recall if this has been mentioned. If so, it will be what, ~0.9-1m above the top of the tank?? (and whatever liquid you have filled the tank with).
Many pool pumps will not self prime at this height, so it might pay to experiment a little and even have a way to help it prime.
One other consideration Shane...it has been mentioned that the problem has happened just after leaving port with a full tank, as well as anywhere in between down to a 1/4 tank.
If it is something in the tank, this means it is 'wafting' around and not 'floating' around, i.e. the object's relative density is greater than that of ULP which is ~0.76 depending on temp. However, how much greater we don't know.
If it is greater than ULP but less than water (1.0) , the object will then float when you fill the tank with water. This might make it harder to find/extract.
If you empty it a few times without finding the culprit, I would still try to flush it (one end to the other) as well when there is a few inches of water still in the tank, ie, force water down the pickup if you are sucking from the filler.
You might not be able to get much flow down the pickup, but in my mind it would still help.
Good luck!
Cheers
Brendon
Sent from my iPhone using Tapatalk
Posting Permissions
Reply With Quote