Ka24de fuel system

[xzile609]

Ok so I have a 68 510 I really would like to use the stock fuel lines.

 

The feed line is 1/4 and the return is 5/16. I wanna keep the 1/4 feed line because on the tank the 1/4 outlet has a pick up tube inside. The 5/16 outlet does not.

 

The problem is I bought a walbro 255 external pump but the fitting that come with the install kit are 12mm barbs =to 3/8 fuel line. I want to covert the fittings down to 1/4 but the threads on the pump are walbro specificic. I've tried 1/4 NPT fittings and they leak at the threads.

 

Does anyone have an idea of how I can safely down size the fitting to 1/4 barbs from 3/8.

[INDY510]

5. Fuel. You can either graft-in an intank fuel pump into your stock 510 tank, or you can run an external pump (such as an inline Walbro 255LPH). I prefer the external method, since welding on a fuel tank can result in warping and leaking (unless you are really good with a TIG).

Your feed and return lines need to be at least 5/16" size tubing. If your return line is too small, the fuel pressure regulator wont be able to bleed fuel off fast enough to keep the pressure down where it should be. The pump will be controlled by a relay, which is controlled by the ECU. Make sure the pressure (feed) line from the pump goes directly to the fuel rail. The return line (back to the tank) comes from the fuel pressure regulator.

[xzile609]

5/16 is still smaller than 3/8 I've herd many people use the 1/4 line. That information is somewhat valid. Or they have never seen the actual walbro kit.

 

So I need to go 5/16 and stretch the fuel line? I assume the 1/4 barb will be hard to seal at the tank also. This info seems more viable for 1971-73 510