What is the correct size fuel line?

[pbjman]

What is the correct size fuel line? I am re-plumbing my bike and need to know the correct sizes for the fuel lines and vacuum lines thank you

[pbjman]

The second part of my question is does it need to be the black
fuel line or can it be the clear vinyl tubing

[natemoen]

1/4 is the correct size, some have used 3/16 and not used clamps.

Do not use the thick black double walled automotive line. It often flakes off when you push it onto the barbs and can get stuck in the float valves.

You need to use the single walled motorcycle or atv fuel line. Most go for tygon line because it will stay flexible longer than the cheap stuff.

But whatever you use IT MUST BE FUEL LINE! Don't just use cheap vinyl line that will slowly melt over time.

[Aches n Pains]

What type of fuel line do you guys generally use? Where do you get it? I have found that the Tygon tends to get stiff.

Thanks

[jjz28]

I used the fuel line from advance that is clear but I will be changing that to the tygon. The clear line from advance has worked fine but it gets stiff and I don't want it to get so stiff it breaks. I have only had it on there about 8 months and its pretty stiff. Also, look for the diagram someone on here had drawn on how to run the fuel lines with filters. I don't have the octi so I ran mine like that at it keeps them from kinking and they flow good. If you have the octi, I would not know how to route that. Make sure you get enough so you don't just run it straight to the petcock, you want it to loop around the airbox boots like in the diagram. Hope this helps, I just don't want you to buy something that will stiffen up and break or wont kink.

[TADracer]

Everybody has their own school of thought

Everybody has their own school of thought on fuel line and I certainly respect what anyone wants to use that suits their bike and style. Kind of like what sort of spark plug you use or what kind of motor oil...its a choice.

I have always used 1/4" black fuel injection line, just like you get at the auto parts store and apply it using the 'keep it simple' rule. Never any flaking on the inside or tearing or failures. In fact the only flaking I have ever encountered is on the outside covering from taking clamps on and off. And yes, do use clamps on this type of line.

Here is the caveat....like everything else you get what you pay for. If you buy cheap twenty cent single-wall rubber fuel line you will get that kind of performance. If you spring for the more expensive high-pressure fuel injection line you will have many years of good service. But like any line, after several years (about ten) it will harden. It just does not harden as fast as Tygon or the other high-dollar stuff on the market. But when it does finally start to harden it will not crack open and leak like single wall line will.

One other thing, if you leave your octy in place then the thicker wall of rubber fuel line may make for some tight fitting. Again, that falls into the 'keep it simple' thing.

Now that is just my take on it and like I said, it is a choice you have to make.

[DGXSER]

It is indeed a choice, and there is no right answer. For me, I like to buy the colored see through stuff at Home Depot made for use on lawn mowers. They use to carry Briggs and Stratton, of course it is some off brand now. Been using it for years and had good luck. It does get stiff and develop a memory, however I have never used clamps on it, and it has yet to break.

TAD has had good success with rubber tubing. Me, I chased a leaking float valve for hours and hours before I narrowed it to the double wall fuel line I was using with the rubber inside. For me, it did flake off on the fuel T's and kept sending little love plugs to my carb fuel valves.

[dpotter58]

I bought some from the local marine supply. it's made to handle the ethanol. I also use 1/4 tygon...

[trbig]

TAD has had good success with rubber tubing. Me, I chased a leaking float valve for hours and hours before I narrowed it to the double wall fuel line I was using with the rubber inside. For me, it did flake off on the fuel T's and kept sending little love plugs to my carb fuel valves.

That's the reason I also put cheap inline filters there before it goes to the carbs. Generally, you'll take the tank on and off many times before you remove the carbs. On and off is where you get the flaking.. if it's going to do it. BUT.. if the carbs ever do come off, I just go ahead and replace the line then. New line isn't going to flake on install.

[BA80]

Just about anything will harden exposed to fuel except the rubber and you can't see the fuel flow through that on top of the flaking.

1/4" Tygon seems to work the best for fuel in my opinion. Not certain of the vacuum line size, I've always just taken a piece into the parts house and matched it.