NT carb fuel line size ?
- Thread starter NINETOE
- Start date
3/16" or 5mm. 1/4" is just a little too large and will require a clamp. Some will tell you that the line must be 1/4" for proper fuel flow but if you check the inside diameter of the petcock and the barbed nipple on the carburetor you'll see they are much smaller than 1/4". A large fuel line will not flow more fuel than they will allow. Unless you're running a monster modified engine and running WOT all the time the stock fuel line size will suffice.
Fuel flow is important however. You'll want a steady stream when you disconnect the line from the carb and open the petcock. Dripping indicates a restriction possibly in the petcock or the in-tank filter.
By "braided", do you mean fabric or stainless steel braid?
Tom
Fuel flow is important however. You'll want a steady stream when you disconnect the line from the carb and open the petcock. Dripping indicates a restriction possibly in the petcock or the in-tank filter.
By "braided", do you mean fabric or stainless steel braid?
Tom
Davezilla
New Member
Best antique look would be to make the line out of copper tubing, you would need to modify the petcock outlet or get a different one, an old brass unit would look sweet with a copper fuel line as well as one of those old style glass bowl type fuel filters. You can use copper tubing but it will need a loop or 2 in just the right places to allow the line some flex room both for easier installation and some resistance to shock and vibration... similar to how brake lines are looped coming off the master cylinder in most cars. The loops don't always have to be round either, oval shaped loops look really cool and give a nice retro look too.
The fuel inlet on these carbs are also the screw in type so making up fittings on both sides of the line is very doable.
You can use line as thin as 3/16" and be just fine... the needle and seat valve is what dictates how much fuel can enter the carb how quickly, and ultimately, the main jet is what dictates how much fuel can go into the engine at WOT, so as long as the line is at least 1 1/2 times the size of the needle and seat valve you'll be ok.
The fuel inlet on these carbs are also the screw in type so making up fittings on both sides of the line is very doable.
You can use line as thin as 3/16" and be just fine... the needle and seat valve is what dictates how much fuel can enter the carb how quickly, and ultimately, the main jet is what dictates how much fuel can go into the engine at WOT, so as long as the line is at least 1 1/2 times the size of the needle and seat valve you'll be ok.