Fuel line replacement

[Tor-King]

I am needing to replace the fuel line from the fuel pump to the filter on my 3CV.  Obviously, to find the OEM "formed" line is virtually impossible.  Is there a high quality fuel line that others have used that is a good replacement?
Thanks again,
Dean

[FJmonkey]

Automotive fuel line has a thicker wall and does not route as well as the pre-formed Yamaha. But I did manage to replace the main line from the petcock to the Y on my '86. The original clamps had to be replaced with steel hose clamps. Others have altered the routing with success as well. I have also heard that you can get fuel line from Honda that has the thinner wall like the Yamaha line.

[Pat Conlon]

Do you still have your stock air box Dean?

Much more room for line routing with UniPods.

[Tor-King]

Hey, Pat and Mark.

Mark: I found the automotive lines also to be "thick-walled".  The issue is that the measurements are not in metric like our FJ lines.

Pat:  I do have the original airbox installed on my 3CV.  Everything is in too good of shape to change at this point.

NEW question: What are the dimensions of the line that is pump fed?  I know the gravity fed carbs have a bigger I.D.  My current line is truly too difficult to measure as it is inflexible and for being on the filter and pump nipple for so long I think it has taken on new dimensions...

Dean

[FJmonkey]

6MM [.236"] ID for the fuel pump, 10MM [.393] ID for Gravity feed. Or, 1/4 ID for fuel pump and 3/8 ID for GF... 1 inch equals 25.4 MM. So 6MM divided by 25.4 equals 0.236 inches...

[ribbert]

.... I found the automotive lines also to be "thick-walled". 

Dean

Most of the widely available (auto stores) fuel line is high pressure for injection but as it can also be used for low pressure and cars allow for more free flowing routing, it tends to be all they stock.

You can get elbows, T's and joiners that eliminates the need for tight bends.

The other option is to order a metre of low pressure hose over the net. I just had a look on eBay, there's pages of it, any size you want, including very flash looking steel braided line. Get a bag of proper clips while you at it, they're only about 10c each.

IMO

Noel

[red]

I am needing to replace the fuel line from the fuel pump to the filter on my 3CV.  Obviously, to find the OEM "formed" line is virtually impossible.  Is there a high quality fuel line that others have used that is a good replacement?  Thanks again,
Dean

Dean,

I would consider using straight runs of fuel tubing, and make all the turns and tees with brass fittings.  Any size equal to or larger than stock would be fine.  These guys make all sizes, just to show some possibilities:

https://fastfittings.com/collections/brass-hose-barb-fittings

[FjLee]

I am needing to replace the fuel line from the fuel pump to the filter on my 3CV.  Obviously, to find the OEM "formed" line is virtually impossible.  Is there a high quality fuel line that others have used that is a good replacement?
Thanks again,
Dean

I wanted some after-market fuel line for my 1984 USA FJ1100.  I had a difficult time finding anything dimensionly useable.  It was all too thick.  Finally found some that worked well.  Here is a copy/paste from my "maintenance log": 

"I found  Motion Pro line marked 5/16"/8MM.   P/N 120042.  Black hose, felt almost like rubber, and was quite flexy. It had .5 OD and ID approx 5/16"/.312".  With grease, that ID would reluctantly accept the .430"  barbs.  I bevelled the mouth of the hose with Dremel. on both ends, to give the barbs a chance to get started in.  Also greased and rammed in each end of the hose as large as possible drill bits to stretch the line and prep it for installation. This line was $6.95/ft.  Got 2 ft.  Tho the line didn't seem inclined to kink/collapse, I did put a VERY tight fitting coil spring on the OD of the new line to hopefully prevent hose collapse where it bends around.  Don't try to get hose to fit over the barbs by dipping ends in boiling water.  That'll cause the hose ID to shrink!!"

  This hose has now been in service for 2-3 years, and has been drama-free.

FjLee.......... Denver CO  ..........1984 FJ1100

[red]

Dean,

You can also leave one-half inch of the stock OEM fuel tubing on the bike inlets and outlets, and find some size of fuel tubing that fits well, right over the OEM tubing. 
Install the new fuel tubing to completely cover the OEM tubing, use good (tiny) screw-type hose clamps, and we won't tell anybody.       
I'd still use brass barbed fittings (with clamps) in the new fuel lines, to make any 90 degree turns and tees that may be needed. 

If you sneak in an extra tee fitting somewhere south of the fuel pump, with a shut-off valve, you would have a convenient way to drain the gas tank,
for any maintenance jobs under the tank.

[Flynt]

"I found  Motion Pro line marked 5/16"/8MM.   This hose has now been in service for 2-3 years, and has been drama-free.

I used similar tubing sourced at Cycle Gear...  Specifically meant for fuel.  Don't need hose clamps for gravity feed since the hose fits VERY tightly, but I'd use clamps on the pressurized side of the fuel pump bikes.  You can get a variety of colors and transparencies.  Mine's only been on for a few months, but appears to work perfectly.

Frank

[ribbert]

...... Don't need hose clamps for gravity feed since the hose fits VERY tightly......

Frank

That would depend entirely on the type of fuel hose. Most of the common varietes are fairly stiff and a "VERY tight fit" is only going to encourage the end eventually splitting. Correct size fuel line should not have to be unduly forced over the fitting.

It's good practice to always clamp fuel lines, not take on punt on where you think you can and can't get away without it.

IMO

Noel

[56 CHEVY]

Is there any reason why this fuel line could not be used on a gravity feed bike?

https://www.mcmaster.com/#5552k27/=172xzjn

[FJmonkey]

Flexibility:   Very Flexible

This will be a problem if you don't manage the hose when it gets hot and "Very Flexible". The hose may kink and then cut off the fuel supply. This can be managed a few different ways. A larger stiffer piece of hose in the areas where it may kink (like the OEM hose) or wrap some wire around the hose in the kink areas. Even this stuff may work http://www.pro-tec-toproducts.com/pro-tec-to-wrap.asp. Another member here posted pictures of wire wrap solution and it looked like it works really well.

[simi_ed]

Is there any reason why this fuel line could not be used on a gravity feed bike?

https://www.mcmaster.com/#5552k27/=172xzjn

It sounds plausible, maybe worth a try.  IIRC, the fuel lines are 8mm (5/16"). Perhaps this might be a better choice 5/16_PVC.  For the minimal cost, maybe order both sizes to be sure. If I were going to do a test like this  I would keep a close eye on this for 6-12 months to watch for deterioration of the lines. Failed fuel lines can be catastrophic!!!

[racerrad8]

A couple of members have used this line. We ordered some and planned on using it on a bike here but it is too flimsy and kinks very easily. We ended up not using it as we did not want to risk having fueling problems.

Ed, the gravity fed bikes use 10 mm I.D. lines.

Robert - RPM