Fuel line - 5.56mm to pump, 8mm to Twin Carbs?

[Walt]

Just got some new R9 fuel hose from machine7 to replace my current hose. Looks like the Fuel hose on my bus is 5.6mm to the pump and 8mm to the Twin Carbs.

From a bit of searching am I right in thinking the 8mm from the manual pump to carb is intentionally to reduce the pressure at the carb? The carbs are weber 44 idf's.

So thinking maybe I shouldn't swap the 8mm to the 5.6mm as this would increase the pressure? Anyone else run different size hoses to carb?
Any recommendations on where to get R9 8mm fuel hose?

Thanks.

 

[sparkywig]

The inlet banjos on Weber carbs are normally 8mm rather than 5.6mm
I use Gates Barricade 5/16" (8mm) fuel hose from the pump to the carbs. You can get it from Moss Europe.

https://www.moss-europe.co.uk/ethanol-proof-fuel-hose-by-gates.html

 

[Walt]

Thanks Sparky - Have now ordered some!

 

[K@rlos]

Have you got a pressure regulator? IDF’s like a max pressure of 3.5psi, a stock pump will make close to 10psi at speed.

 

[Walt]

Have you got a pressure regulator? IDF’s like a max pressure of 3.5psi, a stock pump will make close to 10psi at speed.

I haven't - is there a particular one I should be looking to get?
Any ideas what issues is it likely to cause if a regulator isn't used?
As for the pump, previous owner had ran an electric pump but swapped back to the stock one.

 

[K@rlos]

Have you got a pressure regulator? IDF’s like a max pressure of 3.5psi, a stock pump will make close to 10psi at speed.

I haven't - is there a particular one I should be looking to get?
Any ideas what issues is it likely to cause if a regulator isn't used?
As for the pump, previous owner had ran an electric pump but swapped back to the stock one.

You’ll flood the carbs and it will run crap, I suspect the pump you removed was a set pressure 1. If your set on using a stock pump get a filterking, they are a regulator and a filter all in 1