Ethanol Resistant Fuel Tubing

[fishfun83]

I am rebuilding my 3 carburetors on a 80hp Yamaha 1997 model outboard motor. The fuel lines to each of the 3 carburetors is the original line using clips to form a manifold. The existing lines almost look like they are made of a black plastic material. Anyway, can someone recommend a fuel line that is ethanol resistant to replace the old hose. Thanks,

[robert graham]

Mine is a 1999 C90 Yamaha similar to yours and it has all the original fuel hoses/lines with no apparent ill effects or deterioration from the ethanol fuels, which I have used regularly since it became available....if your fuel lines look fine then maybe just leave them....if I ever have to replace a fuel line I'd buy the original equipment hoses from the Yamaha dealer....it's not cheap but it's very good quality...

[dorf]

From my experience and just my 2 cents---( If you are using fuel with ethanol)---Replace ALL the Fuel Lines going all the way back to the tank.

When you cut them open you will discover a buildup, similar to the hollow noodle that has formed inside , Restricting fuel flow and causing more build-up to occur.

Check your engine mounted filter also and if you have not, install a Yamaha 10 micron fuel water separator filter.

Just my 2 cents

[Tucker]

Well it's come down to a simple question. Did Yamaha use ethanol resistant fuel lines on their motors in the late 90's?? I'm always squeezing those formed hoses feeling for that crunch. So far so good...

[fishfun83]

Thanks everyone for your responses. I looked up how much it would cost to replace the pieces of hose that make up the manifold and the cost from Yamaha is well over $100 and might even approach $200. The hose is not bad, still pliable with no cracks, but I am concerned about varnish lining the walls of the hose. Think I am going to remove the manifold assembly and spray with carburetor cleaner to see what comes out. If I get any varnish residue, I will label and disassemble the manifold and clean each piece individually.

[robert graham]

I looked up how much it would cost to replace the pieces of hose that make up the manifold and the cost from Yamaha is well over $100. The hose is not bad but I am concerned about varnish lining the walls of the hose. Think I am going to remove the manifold assembly and spray with carburetor cleaner to see what comes out. If I get any varnish residue, I will label and disassemble the manifold and clean each piece individually.

That should be fairly easy to do and maybe give you some peace of mind regarding the condition of your fuel lines. I regularly check/clean my motor mounted fuel filter for any fine particles that might indicate fuel line deterioration, and drain each carb onto a clean white rag to look for water/debris that could accumulate there....so far, so good!....

[rodbolt17]

the factory Yamaha stuff holds up well.
better than most.
as far as alcohol resistance.
its about the same as some water resistant watches.
some lines fail faster than others.

[throrope]

BING ALCOHOL RESISTANT<br>FUEL LINE from Aircraft Spruce

Bought it, but still in the padded envelope.

[99yam40]

BING ALCOHOL RESISTANT<br>FUEL LINE from Aircraft Spruce

Bought it, but still in the padded envelope.

It should last a long time sitting in the envelope as long as it does not get thrown away.


Maybe not
"Fuel Line SHOULD ALWAYS BE INSPECTED CAREFULLY BEFORE EACH FLIGHT and REPLACED EVERY YEAR. Fuel line can be damaged by UV rays and coastal environments."

[Tucker]

I believe all the hoses under the cowl are pre-formed.

[FLCoyote]

The fuel lines on my 2005 F90 were not ethanol resistant and the insides crumbled about three years ago. I had to have all new fuel lines and a new VST filter installed at a cost of $451. My dealer told me that they didn't start using ethanol resistant fuel lines across the board until 2006. The inside of the old fuel lines looked a lot like corn flakes.

FLCoyote

[robert graham]

The fuel lines on my 2005 F90 were not ethanol resistant and the insides crumbled about three years ago. I had to have all new fuel lines and a new VST filter installed at a cost of $451. My dealer told me that they didn't start using ethanol resistant fuel lines across the board until 2006. The inside of the old fuel lines looked a lot like corn flakes.

FLCoyote

Must be some big differences either in the fuel lines or the fuel itself, because my 1999 C90 does have all the original fuel lines. I use any 87 octane gas with up to 10% ethanol, Ringfree and Stabil all the time. Maybe Yamaha has tried several different vendors/sources for their fuel lines...with different degrees of success?....

[99yam40]

My 99 C40 lines are fine too

Maybe there was something from tank that was coating his lines if they looked like that

[robert graham]

My 99 C40 lines are fine too

Maybe there was something from tank that was coating his lines if they looked like that

Yep, maybe from the tank....wonder if fuel got old and got that phase separation from the ethanol and water?....

[FLCoyote]

Crumbling Fuel Lines F90

My boat gets a lot of use and I always treat the fuel with Stabil. My Yamaha Dealer told me that I was number five or six with the bad fuel lines. If you do some searching on the internet you can find pictures of the defective lines and the crumbled inner linings. If you squeeze the lines and they feel crunchy, they've gone bad. If they've gone bad you need to replace all of your filters and possibly clean your fuel tank. Yesterday I replaced my fuel/water separator with a Racor 2 micron and the clear bowl. I jacked the front of the boat up to get the fuel to the rear of the tank, put it on the hose and started it up. I was somewhat amazed that as I watched the clear bowl on the Racor got 2/3 full of water in about 15 seconds. I think the Racor 2 micron will prevent debris getting through the system and may just need to be replaced frequently to clean the fuel tank. I don't know how frequently, but plan to change mine after 20 hours, probably twice, then go to 100 hour intervals.

Be Safe, FLCoyote