fuel starvation when heeled

PabloPicasso

PabloPicasso

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THE TANK ON A 24FT SAILBOAT IS BELOW AN AFT LOCKER BUT ABOVE THE engine when sailing upright and level. Gravity fed fuel seems to work fine. When heeled to port, however, fuel starvation ensues, and the engine dies. So far has always re-started sometimes after re-bleeding the fuel.

What is the best fix for this without moving the tank? Fit a fuelpump, fit a seperate 'header' tank in the gap above engine? Sometging else??
 
You need to know what's happening. Does the flow stop because (a) the level drops below the gravity feed height needed but the pickup is still submersed in fuel or (b) is the fuel below the pickup level if tank contents low and it's heeled?

If (a) then installing an electric pump should cure the problem. If (b) some tank mods are necessary.
 
GrahamM376 said:
You need to know what's happening. Does the flow stop because (a) the level drops below the gravity feed height needed but the pickup is still submersed in fuel or (b) is the fuel below the pickup level if tank contents low and it's heeled?

If (a) then installing an electric pump should cure the problem. If (b) some tank mods are necessary.
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If the engine is Petrol be bloody careful...

With a fuel pump or raising the tank, if any failure in carb you can end up with petrol where you REALLY do not want it :eek::eek:

Maybe check for fuel/air leaks in piping to carb or engine?
 
PabloPicasso said:
THE TANK ON A 24FT SAILBOAT IS BELOW AN AFT LOCKER BUT ABOVE THE engine when sailing upright and level. Gravity fed fuel seems to work fine. When heeled to port, however, fuel starvation ensues, and the engine dies. So far has always re-started sometimes after re-bleeding the fuel.

What is the best fix for this without moving the tank? Fit a fuelpump, fit a seperate 'header' tank in the gap above engine? Sometging else??
Click to expand...

Quick, cheap fix is fill the tank.
 
Check that the fuel take-off is at the centre of the tank, not off to the port side as on my boat. While idling the engine to let it cool after hoisting sail on port tack, I ran out of fuel when the tank was 1/3 full. Now keep it full as possible, and re-locating the take-off to the centre of the tank (where there is a take off for the not fitted diesel heater) is on the list of things to do,
 
GrahamM376 said:
You need to know what's happening. Does the flow stop because (a) the level drops below the gravity feed height needed but the pickup is still submersed in fuel or (b) is the fuel below the pickup level if tank contents low and it's heeled?

If (a) then installing an electric pump should cure the problem. If (b) some tank mods are necessary.
Click to expand...

That is an interesting answer. I hadn't considered that the pick-up might be above the fuel level some of the time.

What kind of mod did you have in mind?
 
Fuel pump power enough?

Is the fuel pum[p on this 9hp single cylinder engine likely to be powerful enough to suck the fuel up from the tank when heeled if the flop tube isnt the problem?
 
PabloPicasso said:
What is the best fix for this without moving the tank? Fit a fuelpump, fit a seperate 'header' tank in the gap above engine? Sometging else??
Click to expand...

Just as an after thought and before you go spending and if all else fails is I assume you tank is clean internally ?

IE: if you have gung in the tank bottom as you 'heel over' to starboard 'it may' be blocking your outlet pipe but then clears when you come back 'upright' and bleed the system again.

Mike
 
PabloPicasso said:
That is an interesting answer. I hadn't considered that the pick-up might be above the fuel level some of the time.

What kind of mod did you have in mind?
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One suggestion above could solve the problem if my understanding of a flop tube (never seen one) is correct in that it's a flexible pickup pipe which will move around the tank as it heels. This of course still relies on the fuel level being high enough to gravity feed as the flop tube could even further downhill.

If it won't gravity feed then I think you're possibly looking at a low down small day tank, maybe only the size of a gallon can, which will fill by gravity when upright, with a small electric pump such as this http://www.ebay.co.uk/itm/ELECTRIC-...arts_Vehicles_CarParts_SM&hash=item3cc5aadfbc from that to the engine. The whole setup should only cost about £50. As a test, you could use any plastic fuel can with holes drilled in the filler cap for the pipes.
 
My petrol hedge trimmer has a flop-tube, if that's what it is called. A flexible tube with a metal filter to keep it at the tank's lowest point.
Every so often it breaks, and I get a welcome excuse to stop cutting the hedge. Seems that immersion in fuel and constant movement give it a hard time.
I'd think that there are more reliable methods of curing fuel starvation for boat engines.
 
earlybird said:
My petrol hedge trimmer has a flop-tube, if that's what it is called. A flexible tube with a metal filter to keep it at the tank's lowest point.
Every so often it breaks, and I get a welcome excuse to stop cutting the hedge. Seems that immersion in fuel and constant movement give it a hard time.
I'd think that there are more reliable methods of curing fuel starvation for boat engines.
Click to expand...

aircraft use floptubes, apparently, I wonder how reliable they really are...:eek:
 
PabloPicasso said:
aircraft use floptubes, apparently, I wonder how reliable they really are...:eek:
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Are they changed on routine maintenance? Would you do the same, or like me, wait 'till it breaks?
Must admit though, my hedge-trimmer is an Aldi "bargain".
Just thought of another possible disadvantage. Unlike a fixed tube, a flop-tube would seem a good way of picking up sludge from the tank bottom.
 
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