Hose Diameters ?

[SkiDad]

Hi Guys, been replacing fuel hoses recently. I know it doesn't matter a lot, but I believe the guy who had this boat put wrong sizes on. I had originally thought all the fuel lines were 1/4" because that was what he used - when I started doing it I realized that the connectors are 5/16. So i ordered the correct size line.

So in my picture my 5/16 gray hose is hooked to the 5/16 barbs.

I have a question on re-circulation lines - i used 3/16 line because that is what it had - but i wonder if that is wrong too (Red Arrows) The barbs look like they could be 1/4" but I used the 3/16 - it went on very tight. I could use 1/4" on those but probably need hose clamps of some kind.

finally what is the hose marked with the yellow arrow ? That is one piece I haven't changed yet.

 

[jerryjerry05]

Yellow hose, is the impulse/ vacuum hose.
​It needs to be hard.
It makes the pump work.

​Most Force inlet fuel lines were 1/4in.
​Then some places on the motor use a bigger line.


You mean 3/8 not 3/16??

​The lines don't have hose clamps now because there is very little pressure on the return or recirc system lines.

A customer changed his 150 Force for a 250 Mercury.
He had trouble with it from the git!!
Turns out he didn't change the 1/4in fuel line to the 3/8 Mercury used,
​It would starve without enough fuel.
​Stall and then start right up and run for a bit then stall again?????

 

[SkiDad]

when I started messing the boat had

1/4" lines on all fuel lines
3/16" lines on re-circulation

now I have

5/16" lines on all fuel lines
3/16" lines on re-circulation

seems to run the same weather 1/4 or 5/16 lines. One thing I did notice with the cover off on the lake the fuel filter went to 1/2 full on idle and then all the sudden filled up again - this was shortly after I started it.

 

[jerryjerry05]

My inline filters never get full.
Or at least when I'm looking at them???
​They might fill up when I'm running at speed going down the river?? I never looked??