Topic: '70 CB 750 Fuel Line Routing

[major domo]

How is the fuel line routed for carb #'s 3 & 4 on a '70 CB750? Does it pass under the carb mounting bracket, them up to the spigot between the carbs? Also, is that fuel spigot supposed to point up or down? Might as well  ask about carbs 1 & 2 as well. Thanks in advance!


Ken

[evinrude7]

i'm not sure if anything is terribly different between any of the sohc bikes as far as general routing of fuel lines.  perhaps i'm wrong.  i've always been told take the most direct route and always head down hill from tank to carbs.  both of my spigots are down hill toward carbs. 

[Johnie]

The 1 & 2 fuel line on my KO's run over the top of the air box rubber then angle down to the petcock. Carb 3 & 4 it runs behind the stay plate and into the petcock. Both fuel T's are angled up between the carbs. Angle them the best way to not have a crimp.

[MauiK3]

I had a little of the same trouble. Mine are like Johnnie's. My problem was the Yamiya grey fuel line. It was a little prone to kinking especially if it was too long. I got some more original looking black line that was a little thinner wall thickness. Problem went away.

[major domo]

Thanks for the replies!

[HondaMan]

I had a little of the same trouble. Mine are like Johnnie's. My problem was the Yamiya grey fuel line. It was a little prone to kinking especially if it was too long. I got some more original looking black line that was a little thinner wall thickness. Problem went away.

Yep, been here, done that, too...the K0 may or may not have the hole in the carb mount plate for the fuel hose that goes to the far side. This was added at the K1, which had 2 holes for the hoses to make sure the hose could not get kinked when they switched from the 5.0mm hose of the K0 setup to the 5.5mm hose of the later ones. Today, Honda is only offering an extra-thick (because it is ethanol-resistant) 5.5mm hose, although you can still try to order the 5.0mm part. Once in a while I can get some, but it goes quick! Look in the CB500-4 for the part number, if the fiche hasn't yet been "unitized".