Decent Fuel Line???

[viclioce]

What do you guys use? I’ve bought this clear fuel line at O’Riley’s in the 1/4” diameter but it seems the worm drive clamps I’m using just keep cutting into the fuel line, causing it to leak! I don’t want to replace it again. Any suggestions? I would prefer a clear line, but will take any suggestions at this point! Victor

[thrownchain]

I use Oregon brand, it's yellow, but I like it. I use 3/16", heat the ends and push over the fittings. I bought japanese style spring clamps off ebay and use those. Or a quick twist of safety wire does the job also. Be careful of sharp ends.

[hodakamax]

Good question Victor. Ace hardware had some options one being fuel line for chain saws. A little expensive but it doesn't take much. Yellow but clear was the color. My input.

Maxie

[taber hodaka]

Cutting into the fuel lines could be over tightening. The original clamps were spring loaded at least on the early ones. Some gas lines just don't seem to work well. Good advice will be coming your way. --------------Clarence

[Darrell]

There's clear plastic tubing, AND clear fuel line -- formulated to be ethanol and gasoline compatible. The former is for oxygen lines, aquarium pumps, etc. and will swell, go brittle, and leak at the fittings when used as fuel line.

[Bill2001]

I use a 1/4" Tygon tubing that I get at a local industrial supply. The carb fuel inlet on my current-stock Mikuni is larger than the usual 6mm taps used; I use 5/16" (8mm) Tygon. The plastic sintered-bronze filter fits either 6mm or 8mm tubing and is used between the carb inlet and the T-fitting. I usually don't need to use hoseclamps, but if I do, it is the small wire type. Screw-type are for thick-walled rubber tubing and should not be used on thin Tygon.

[go_hercules]

I have the answer on this one.

After lots of experimenting, I discovered a clear fuel line that is gasoline resistant, ethanol resistant, pliable, and lasts a very long time without hardening. I use it on all my vintage bikes and have been for quite a few years. It is Motion Pro Premium Fuel Line. It is not Tygon, it is not vinyl. I believe it is a polyurethane blend. All I know is that you can't go wrong with it and it is easily available. My local shops usually don't carry it but order it for me quick enough.

https://www.motionpro.com/motorcycle/to ... fuel_line/

[Hydraulic Jack]

From what I can find, and from other informed source, MP probably isn't "Tygon", which is a proprietary fuel line made of PVC lined with FEP. So if it isn't Tygon, it is probably just PVC. Anyway, in the fine print, it says to use the stepless ear clamp. I think it is easier to use reusable ring clamps than the crimp type.

Vic, the line you have is probably fine, if it is the right ID. Just don't use a screw clamp, or if that's all you have, tighten less vigorously. The line should press onto the fittings. If it is a loose fit, and that's why you are clamping down on it, it's the wrong size. You might need 3/16" line or metric line. Measure the fittings. The ID of your line should be smaller than the ferrule diameter on the barb fittings, and the fit should be snug without clamps. Hodaka and a lot of other bikes used simple spring rings because properly fitted line needs only a bit of security to hold it in place. The clamp is not there to prevent leakage, it is intended to prevent slippage.

[viclioce]

OK, Jack. Yes I’m sure I was over tightening because when I open both peacocks, one side pushes hard against the other side causing the hose to leak.

The line fits snugly, but I don’t have to heat it to make it go on. So I guess I need to find better style clamps. The worm clamps cut into it. It holds OK initially but with the removals & reinstalls involves with float adjustments & tank removals for electrical harness access, the clamps have been loosened & tightened a lot.

Sometimes I can’t tell if it’s the floats overflowing or just fuel leaking down the fuel line, because it all drips from thd same place on the bottom of the carb, where the bowl overflow is. Victor

[matt glascock]

On the same theme, what are some options for managing a significant discrepancy between the fuel outlet on the petcock and the inlet on the carburetor? This is the case on a post-vintage race bike of mine. What I'm doing is using a short segment of PVC fuel line on the petcock outlet then placing the conducting fuel line over that which is then secured with a worm drive clamp. Clunky but functional. I'd like something that has flexibility but is not thin and wimpy. Any suggestions.

[Hydraulic Jack]

Look for something like this in a fuel compatible material, preferably in a barb to barb configuration:

https://www.piecoweb.com/us/grey-acetal ... gKS3PD_BwE

[matt glascock]

Great Jack. Just what I was hoping for. I didn't know there was such a critter. Hopefully I can find one that is fuel proof. Better yet, brass. Thanks!!

[Hydraulic Jack]

Like this:

https://www.ebay.com/itm/Reducer-1-4-to ... 0677.m4598

[matt glascock]

Precisely. 6mm to 8mm. Barbed on both ends. Brass. Perfect. I just scored a couple. Thanks Jack!

[Bill2001]

This is how I routed the fuel hoses. From the 8mm fuel inlet on the new-stock carb to the sintered bronze fuel filter is a short piece of 5/16" Tygon (originally I used a piece of 1/4" Tygon heated and stretched over the fittings but i worried about failure). A relaxed arc of 1/4" Tygon goes from the filter to the left petcock. That section of hose is cut and the brass T-fitting inserted. A length of hose goes from the T-fitting and the right petcock. Installing the hoses this way gets the lengths right. The hose fits nicely enough so that no hose clamps are needed, and does not form a "set" on the fittings so it can be removed from the petcocks for tank removal.

[viclioce]

Bill. That looks nice! I have my “T” between my 2 peacocks & then a single line down from the bottom of the “T” To the fuel filter.

What size is your brass “T”? Is it 1/4” or a metric size?

What happens with me is the fuel from the right petcock forces itself against the fuel line at the upper left end by the petcock and causes leakage. This is what gas prompted the over tightening of the clamps leading to cause breaks in the fuel line at the petcock!

If I leave a petcock open accidentally I can lose an entire gallon of pre-mix to the garage floor over night. I try to remember to turn the petcocks off, but don’t always remember. I wonder if changing the “T”, to the position like yours, would reduce the upward fuel flow?

I think I will try building the fuel lines again & go with the way you have yours configured. I may also just use spring clamps instead of worm clamps!

I also don’t want my nephew to take the bike home to his garage and forget to close a petcock and have a major fuel spill on the garage floor. Especially since they have indoor access to the house from the garage.

Victor

[Bullfrog]

Bill's routing of the fuel line is highly recommended. One of the advantages of that routing is that only one section of fuel line has a 90 degree bend, the other two have only very slight bends.

Ed

[Hydraulic Jack]

Vic,

The fuel in the fuel lines offers constant pressure regardless of which petcock provided the fuel, dependent on how much fuel is in the tank. Your arrangement isn't causing leakage, nor would rearranging the T change anything. While gravity does create a downward moment, the fuel pressure is actually pushing in all directions all the time. If fuel is leaking around any joint, inspect the joint for cracks or surface damage that would make an imperfect seal against the fuel line, and verify that your fuel line is properly sized for the hardware. I don't recall any stock Hodaka fuel fittings in 1/4".

[viclioce]

OK Jack! Will do! Victor

[viclioce]

Are the brass petcocks 6mm or 8mm? Victor

[Hydraulic Jack]

6mm.

[viclioce]

The problem was two fold. The worm clamps were cutting the line at the petcock, & the floats were out of adjustment. Last time I adjusted the floats, I went in the wrong direction!

We now have fuel flowing properly & no more leaking! Whew! Ordering a bunch of spring clamps and keeping them on hand. And, the packaging for 6mm fuel line & 1/4” fuel Line lists them as the same. So dropped to 3/16” line and heated the ended up to stretch over the petcock & T joints! Victor

[Bill2001]

No. The petcocks and T-fitting take
6mm tubing. 3/16" tubing is 4.78mm.
Too small. 1/4" is correct.

[Hydraulic Jack]

6mm fuel line would be appropriate for 6mm fittings. But the question comes down to available fuel line. If non-metric is all you can find, which do you use?

6mm = 0.236". Quarter inch fuel line should be nominally 0.25" ID. Inside dimensions may or may not match the designation of your fuel line, but if your fuel line is in fact 0.25" ID, that fuel line is actually just a bit too large for a 6mm fitting. The fuel line ID should be approximately the same as the smallest diameter of a barb fitting, not the largest diameter, and should press fit onto the barb such that pulling it off the barb isn't easy to do. Sort of like a Chinese finger cuff, pulling on a properly sized fuel line on a barb fitting causes the line to go snug. If your line is already about the same ID as the largest outside diameter on the barb, it will slip off readily, and you would be relying on the clamp to make it stay and to keep it from leaking.

That is not to say that 3/16" ID line is correct for a 6mm barb, but if the choice is 3/16" or 1/4", I would use the 3/16" because it will be a firm fit on the barb without the clamp. I wouldn't think heat would be necessary to make it fit, but perhaps that depends on what the line is made of and how thick the tube wall is.

I would hope that an improperly adjusted float would not cause fuel to leak from the fuel line above the carb.

[Hydraulic Jack]

And just because it's out there, if you have a Honda shop handy, ask for 5.5mm fuel hose. This is what Honda used back in the day, when Hodaka was still in business. I think you will find it fits the 6mm fittings just fine. It is, however, black, but if you are using a clear fuel filter, you can still see fuel flow.