Fuel Line Failure - Moderated Discussion Areas

  ContinuousWave
  Whaler
  Moderated Discussion Areas
  ContinuousWave: Whaler Repairs/Mods
  Fuel Line Failure

search | FAQ | profile | register | author help

Author Topic:   Fuel Line Failure

BWLucky13 posted 06-17-2008 08:15 PM ET (US)
Just got my Mercury 25-HP FOURSTROKE Bigfoot out of the shop. The mechanic showed me the old fuel line. The lining had turned into gunk that looked like fuel varnish. Has anyone experienced this before? How often should you replace fuel hoses?
jimh posted 06-17-2008 10:24 PM ET (US)
Was the damaged fuel line a rubber fuel hose which was specifically marked as being rated for alcohol-gasoline fuel?
Or, by any chance, was it a silver hose that was part of a portable fuel tank set up?
BWLucky13 posted 06-18-2008 11:44 AM ET (US)
The hose was the original BW setup, a grey-silver color with an internal liner. I don't recall any alcohol fuel reference on it. However, the replacement hose looks very similar to the original. This is a seven year old rig. So, I am wondering if fuel hose should be replaced every five years or so.
Also of interest was that the mechanic removed the inline fuel filter and told me to never use one again. He said the internal motor filter was more than adequate and that inline filters are a common source of vacuum air leaks. Both the fuel line failure and the filter advice were surprising to me.
jimh posted 06-18-2008 12:28 PM ET (US)
Rubber fuel hose used on boats (but not necessarily on portable fuel tanks) has to be clearly marked with the date of manufacture, the rating (usually A1, A2, B1, or B2), and the tolerance for gasoline-alcohol blended fuel.
There have been prior reports of problems with fuel hoses that have a silver-metallic color.
Fuel contained in small portable tanks generally does not collect debris or water, other than having debris or water poured into the tank along with the fuel, and there is some debate on the question of whether or not fuel from such a portable tank needs to be passed through an external fuel filter such as a RACOR fuel-water separating filter. However, if an external filter is installed, and if the suction across the filter is minimal, the fuel pump in the motor really doesn't know it's there. A large RACOR can supply many, many gallons of fuel per hour, and a small four-stroke motor will only consume a few gallons per hour. In most cases the fuel pump in the motor will have plenty of extra lift to pull the fuel through the external filter.
Citing air leaks as a reason not to install a filter is not particularly significant. The fuel system needs to be air tight. All connections in the fuel system have to be properly made and sealed, and there is really no special probability that adding a filter will suddenly cause a leak. Yes, a filter adds three more connections which might leak, but those connections are no more likely to leak than all the ones already in your system.
MaGuyver posted 06-18-2008 12:39 PM ET (US)
I just looked at a silver-metallic hose (as an extra) last night at Sports Authority and it said alcohol safe.
I have a 2004 Montauk that I just bought and did not see a fuel water separator (thought they came with them). Should I put one on or does it make a diff.? I have a 17 gal. external tank.
Plotman posted 06-18-2008 05:06 PM ET (US)
Generally you do not need a fuel filter with an on deck tank. If you buy fuel in sketchy places, you are probably better buying a funnel with a good filter in it and using that when you gas up.
http://www.practical-sailor.com/sailing/fuel-filters.html
Racor also makes a line of filter funnels which I suspect is going to be decent, though the PS test had very good things to say about the $30 west marine filter.
Martino posted 06-18-2008 08:30 PM ET (US)
Fuel line on my Revenge 22 failed. The silver stuff. Looked fine outside, collapsed internally. Cut it into sections after replacement, some sections looked completely closed. Said it was alcohol resistant. Lasted about 5 years. The new line solved my fuel starvation issues.
BWLucky13 posted 06-19-2008 10:13 PM ET (US)
In regards to the inline fuel filter, it was one of those clear cylinder units with a fine replaceable internal screen. The end caps screwed together. So, I can see where it might be more prone to air leaks than a one piece sealed filter unit. The mechanic showed me the internal Mercury filter and it had obviously done a good job of stopping the gunk that reached the motor.
cohasett73 posted 06-20-2008 01:18 AM ET (US)
The best fuel line for the money is polyurethane tubing, virtually indestructable, never hardens, dry-rots, transparent. I purchase it from McMaster Carr.
Tom from Rubicon
jimh posted 06-21-2008 08:59 AM ET (US)
While Tom's endorsement of polyurethane tubing for use with gasoline fuels is unrestricted, another opinion is somewhat cautious:

quote:
[Polyurethane] has exceptional resistance to most gasolines, oils, kerosene, and other petroleum-based chemicals, making PU tubing and hose an ideal choice for fuel lines (although additives in today’s gasoline and petroleum products warrant field testing).
Source: http://www.newageindustries.com/polyurethane_hose.asp
jimh posted 06-21-2008 09:08 AM ET (US)
If you go to the McMaster-Carr website:
http://www.mcmaster.com/
and enter the search term
9148TAC
you will be taken to a result which lists the chemical resistance and compatibility of various polyurethane tubing sold by McMaster-Carr with various chemical classes. Regarding use with gasoline, I note that there is no polyurethane tubing listed which rates "A" (No effect), and some rate as low as 'C" (Not recommended, Do Not Use). A recommendation of "Do Not Use" seems to be in direct conflict with advice from Tom.
Based on this information I would advise caution in using polyurethane tubing supplied by McMaster-Carr with gasoline fuels, particularly with today's blended fuels containing ethanol.
BWLucky13 posted 06-24-2008 09:24 AM ET (US)
There are no markings on the new fuel line. It is simply a dull silver grey color.
I asked the tech about the best way to avoid fuel problems. He said to keep the tank full or empty, but not in between when the boat is not operating.

Hop to:

Contact Us | RETURN to ContinuousWave Top Page

Powered by: Ultimate Bulletin Board, Freeware Version 2000
Purchase our Licensed Version- which adds many more features!
© Infopop Corporation (formerly Madrona Park, Inc.), 1998 - 2000.

Author	Topic: Fuel Line Failure
BWLucky13	posted 06-17-2008 08:15 PM ET (US) Just got my Mercury 25-HP FOURSTROKE Bigfoot out of the shop. The mechanic showed me the old fuel line. The lining had turned into gunk that looked like fuel varnish. Has anyone experienced this before? How often should you replace fuel hoses?
jimh	posted 06-17-2008 10:24 PM ET (US) Was the damaged fuel line a rubber fuel hose which was specifically marked as being rated for alcohol-gasoline fuel? Or, by any chance, was it a silver hose that was part of a portable fuel tank set up?
BWLucky13	posted 06-18-2008 11:44 AM ET (US) The hose was the original BW setup, a grey-silver color with an internal liner. I don't recall any alcohol fuel reference on it. However, the replacement hose looks very similar to the original. This is a seven year old rig. So, I am wondering if fuel hose should be replaced every five years or so. Also of interest was that the mechanic removed the inline fuel filter and told me to never use one again. He said the internal motor filter was more than adequate and that inline filters are a common source of vacuum air leaks. Both the fuel line failure and the filter advice were surprising to me.
jimh	posted 06-18-2008 12:28 PM ET (US) Rubber fuel hose used on boats (but not necessarily on portable fuel tanks) has to be clearly marked with the date of manufacture, the rating (usually A1, A2, B1, or B2), and the tolerance for gasoline-alcohol blended fuel. There have been prior reports of problems with fuel hoses that have a silver-metallic color. Fuel contained in small portable tanks generally does not collect debris or water, other than having debris or water poured into the tank along with the fuel, and there is some debate on the question of whether or not fuel from such a portable tank needs to be passed through an external fuel filter such as a RACOR fuel-water separating filter. However, if an external filter is installed, and if the suction across the filter is minimal, the fuel pump in the motor really doesn't know it's there. A large RACOR can supply many, many gallons of fuel per hour, and a small four-stroke motor will only consume a few gallons per hour. In most cases the fuel pump in the motor will have plenty of extra lift to pull the fuel through the external filter. Citing air leaks as a reason not to install a filter is not particularly significant. The fuel system needs to be air tight. All connections in the fuel system have to be properly made and sealed, and there is really no special probability that adding a filter will suddenly cause a leak. Yes, a filter adds three more connections which might leak, but those connections are no more likely to leak than all the ones already in your system.
MaGuyver	posted 06-18-2008 12:39 PM ET (US) I just looked at a silver-metallic hose (as an extra) last night at Sports Authority and it said alcohol safe. I have a 2004 Montauk that I just bought and did not see a fuel water separator (thought they came with them). Should I put one on or does it make a diff.? I have a 17 gal. external tank.
Plotman	posted 06-18-2008 05:06 PM ET (US) Generally you do not need a fuel filter with an on deck tank. If you buy fuel in sketchy places, you are probably better buying a funnel with a good filter in it and using that when you gas up. http://www.practical-sailor.com/sailing/fuel-filters.html Racor also makes a line of filter funnels which I suspect is going to be decent, though the PS test had very good things to say about the $30 west marine filter.
Martino	posted 06-18-2008 08:30 PM ET (US) Fuel line on my Revenge 22 failed. The silver stuff. Looked fine outside, collapsed internally. Cut it into sections after replacement, some sections looked completely closed. Said it was alcohol resistant. Lasted about 5 years. The new line solved my fuel starvation issues.
BWLucky13	posted 06-19-2008 10:13 PM ET (US) In regards to the inline fuel filter, it was one of those clear cylinder units with a fine replaceable internal screen. The end caps screwed together. So, I can see where it might be more prone to air leaks than a one piece sealed filter unit. The mechanic showed me the internal Mercury filter and it had obviously done a good job of stopping the gunk that reached the motor.
cohasett73	posted 06-20-2008 01:18 AM ET (US) The best fuel line for the money is polyurethane tubing, virtually indestructable, never hardens, dry-rots, transparent. I purchase it from McMaster Carr. Tom from Rubicon
jimh	posted 06-21-2008 08:59 AM ET (US) While Tom's endorsement of polyurethane tubing for use with gasoline fuels is unrestricted, another opinion is somewhat cautious: quote: [Polyurethane] has exceptional resistance to most gasolines, oils, kerosene, and other petroleum-based chemicals, making PU tubing and hose an ideal choice for fuel lines (although additives in today’s gasoline and petroleum products warrant field testing). Source: http://www.newageindustries.com/polyurethane_hose.asp
jimh	posted 06-21-2008 09:08 AM ET (US) If you go to the McMaster-Carr website: http://www.mcmaster.com/ and enter the search term 9148TAC you will be taken to a result which lists the chemical resistance and compatibility of various polyurethane tubing sold by McMaster-Carr with various chemical classes. Regarding use with gasoline, I note that there is no polyurethane tubing listed which rates "A" (No effect), and some rate as low as 'C" (Not recommended, Do Not Use). A recommendation of "Do Not Use" seems to be in direct conflict with advice from Tom. Based on this information I would advise caution in using polyurethane tubing supplied by McMaster-Carr with gasoline fuels, particularly with today's blended fuels containing ethanol.
BWLucky13	posted 06-24-2008 09:24 AM ET (US) There are no markings on the new fuel line. It is simply a dull silver grey color. I asked the tech about the best way to avoid fuel problems. He said to keep the tank full or empty, but not in between when the boat is not operating.