11 Apr Outboard Fuel Line Problems
Our outboard hasn’t been happy lately. The big problem was that it would sometimes refuse to start (and was not flooded) while other times it would start on the first pull. Many times, playing around with the fuel hose – taking it on and off the tank and the motor and pumping it – would get things going again. To make a long story short, after a few days of that, squeezing the primer bulb did nothing – as in, there was no resistence in the bulb and it didn’t expand again after squeezing it.
In other words, all the symptoms of a blockage in the fuel line.
We got a new fuel hose and Dave transferred the old ends and primer bulb. The engine started right up and the primer bulb behaved normally. Okay, basic problem solved.
But I was curious about what had happened – both basic curiosity and wanting to write a post since others we know have had similar problems.
Dave began by trying to blow though the old hose. He couldn’t in two out of the three sections. That confirmed a blockage. Or actually, at least two blockages.
The first cut end of hose that I looked at didn’t seem to have a problem:
But the second one looked a little funny:
It looked like the inside of the hose had melted and twisted.
Turns out, these new hoses have a “non-permeable liner.”
And it can break free (delaminate) from the outer hose and twist itself up. Hmm, I didn’t see that liner in that first bit of hose that I saw. Wonder where it went? I split the hose lengthwise:
Hard to get a good photo, but basically the liner appeared to be totally wadded up. No wonder fuel couldn’t get through!
Everywhere we cut, we found a problem:
In talking with clerks at the local NAPA store, West Marine, other cruisers and outboard mechanics, it seems that we are not alone in this experience.
For the record, this hose was made by Attwood and is not quite 18 months old. We’ve used non-ethanol gas more often than not; when we’ve used gas with ethanol, we used a gas additive as well. I don’t remember the exact designation, but I remember when buying it that it was supposed to be okay for use with ethanol gas.
What I’ve learned (and this is all word-of-mouth and anecdotal):
- All fuel hoses have more problems than they used to.
- Ethanol gas causes more fuel line problems but using ethanol-free gas is not a guarantee you won’t have problems.
- New hoses have an impermeable liner to keep ethanol from degrading the other hose material.
- That liner can delaminate from the outer hose and cause blockages.
- The hoses with the grey outside coating (UV protection) seem to have more problems than others.
- Attwood brand hoses seem to have more problems than some others. They had at least one recall of hoses due to delamination of the inner liner causing blockages.
- OEM hoses seem to last longer before showing problems.
- Automotive fuel hose doesn’t seem to be having the delamination problem but doesn’t have the UV inhibitors and may crack from UV damage.
- When putting hose with the liner on barbed fittings, you have to be very careful that the liner doesn’t separate and “wad up.” It may still do that on it’s own, but you need to be careful not to add to the problem.
Bottom line, however: carry replacement fuel hose and hose clamps! There is basically no sure-fire method to avoid problems either with the liner or UV damage.