Ron,
I think the hose is 8mm or 5/16.  Not trying to give you a hard time by
guessing, but I want to warn you about that formed plastic piece.  That part
was leaking on mine, not the fuel line.  You may want to consider buying one
of those, and only crawling under there one time.  Make sure you by the fuel
injection hose, regular fuel line will not hold up.  Hope this helps.

Good luck,
Doug
'86 GL Westy
Maryland

>I'm puting my 84 back together after replacing the clutch,  CV boots,
>and flushing and refilong the tranny. Just about ready to turn the
>starter, and I think: I'll turn the key, pressurize the system and do a
>visual check. Good think I did. The main fuel line that that enters the
>engine compartment is leaking just above the starter, and driping onto
>the starter wires. The hard plastic line (that comes from the fuel
>pump/filter) goes into a softer rubber line which connects to the formed
>plastic fitting (that connects the undercarriage side of the fuel system
>to the engine compartment side). The soft rubber line (about 3 inches
>long) has two clamps on it. One is a crimp fitting (almost looks
>factory)and the other a screw adjustable type.
>
>Since this line is pressurized, what type of line should I get?
>Any help on the size of this hose? ( I know I have to take it off
>anyway, but would like to stop on the way home and get the hose)
>
>Thanks In Advance
>Ron Semko