Topic: Fuel line that withstand gasoline, ethanol, other chemicals

[PeWe]

I have had some issues with cheap fuel hose from cheap autostore. Hose that collapsed after a few hours of use and blocked fuel line.
I had to fix that before tuning my carbs when lack of fuel tricked me to have jetted too lean....

- Any favourite brands of hose that work well? I ask here when the racers must have more experience of tough chemicals feeding the engines

I got 2 models of hose today, both from Gates, made in USA that must be better than China hose. Gates Universal 3225 (ID 8mm) and probably the better "Gates Barricade® 4219BF Fuel Injection Hose" (ID 7.9mm) that take bio-fuel too.
http://www.gates.com/products/automotive/passenger-car-and-light-truck/fuel-system/barricade-fuel-injection-hose-mpi

Both hoses in 6mm model too. It will be plumming from tank. Begin with short 2x6mm hose - 90 degrees plastic corners, hoses entering the carbs from above. 6mm to 8mm hose to carbs with plastic corners. I must have a consistent flow of fuel via lines that will not fall off or collaps.

[Bob Wessner]

Can't recommend a brand, but look for "nitrile" fuel hose.

[PeWe]

One of the Gates are specified as nitrile hose, 3225 model.
The other that cost more is more exotic. HNBR tube with thermoplastic barrier, aramid fiber reinforcement, CPE cover

I guess the hose I got will due. I'll update the fuel line plumming later.

[Old Scrambler]

I much prefer BRASS corners over plastic or nylon.

[PeWe]

I much prefer BRASS corners over plastic or nylon.

Yes, I should purchase brass before plastic too. But I have only found plastic versions in these small dimensions, 6 and 8mm ID hoses.
I did the fuel line plumming this afternoon direct after work with the "Gates Barricade 4219BF" hose. It is tighter and seal better whith 7.9mm ID and stiffer. 

Carb 1-2 connection got a 6mm hose from tank routed with natural bend to the front of carb 1-2. Here cut hose and connect with 7.9mm hose via 90* corner with reduction. Then another 'natural' bend to the carb T-pipe. It fits well and needed to press hose over the t-pipe. Hose clamp for keep hose in place, not for sealing.

Carb 3-4 needed advanced plumming Short 6mm hose from tank, 90* corner direct with 6mm on other side all the way thur the carb rack over the T-pipe on carb 3-4. Here cut 6mm hose and connect to 7.9 mm hose via 90* corner with reducer, 6mm -7.9mm. Last hose 7,9mm ID and about 6-7cm cm long, (2.5").
The fuel seems to be good routed without kinks or flow blocked by impossible bends, height difference with air bubbles.

[Old Scrambler]

Sanitary install..............may want to take it easy on reserve and find the closest fuel-station.

[PeWe]

I'm not clear about how the old style petcock work. I'm used to the K6 petcock with single fuel pipe. Y-connection to OEM carbs.
The old style petcock has dual pipes out and I'm not sure if both will have same flow @ std position or reserve.

- Do I need to connect the 2 outlets to one via Y-connection - hose and Y-connection again to 2 hoses? This will ensure same flow to both hoses feeding carbs, normal or reserve. But all connections might reduce total flow.

I have read an old thread about the petcock, but I'm not sure...  http://forums.sohc4.net/index.php?topic=11549.0

[dusterdude]

You will need to y or tee it on a single hose carb application

[PeWe]

You will need to y or tee it on a single hose carb application

OK, my carbs have 2 fuel inlets. I can check my petcock (in reserve pos) with a few liter  in the tank and see if it flows from both pipes. I guess there is a risk that they can flow different.

I had single hose carbs last year, Mikuni VM29. I blocked one of the pipes from petcock, a hose with screw + clamp. This scratched my frame every time I lifted the tank. Many lifts....

[Old Scrambler]

With one of your lines going up-and-over the carbs, the minimal head pressure from the tank when on reserve will tend to reduce the flow. The 2-spigot petcock was used by Honda from '62 through '75. I have rebuilt a dozen or more for the CL72 and CL77 models. One of the spigots will tend to drip rather than 'stream' when on reserve. On the twin-carb motors, one spigot fed each carb.   

[PeWe]

With one of your lines going up-and-over the carbs, the minimal head pressure from the tank when on reserve will tend to reduce the flow. The 2-spigot petcock was used by Honda from '62 through '75. I have rebuilt a dozen or more for the CL72 and CL77 models. One of the spigots will tend to drip rather than 'stream' when on reserve. On the twin-carb motors, one spigot fed each carb.   

I guessed that the last liter or 2 in tank can cause bad flow from the petcock.
- Rebuild for better flow? Shorten the brass pipe on petcock inside tank so reserve will come later, flow from both...?

I have another tank, new with same kind of old style petcock. Plus another good tank with new old style petcock....

[Old Scrambler]

They get the job done when clean.  The petcock on my K3 works great and actually shuts the fuel off.............and its totally original, never been apart.

[PeWe]

OK, my petcock is clean and look almost as good as my other new ones. I removed it and changed o-ring and bolts + new bowl that had a small hole leaking fuel.