Fuel line size

[jsaylor]

Just getting ready to order fuel line and primer bulb for my 1987 mariner 150, I measured the inside diameter where it attaches to the tank, it measures 3/8 however the hose looks bulged where attached, the boat shop I called said it would be 5/16, could it be 3/8 from tank to bulb then 5/16 from bulb to engine?
Thanks

 

[Nathan Bond]

The fittings on the current Mercury/Quicksilver primer bulbs are designed to work with both 5/16 and 3/8 ID fuel lines. That, to me would imply that 5/16 would fit your 3/8 tank fitting, snugly as you observed.

 

[Texasmark]

You probably will have fuel delivery problems with 5/16. Go with the 3/8. 150 ponies to feed from a 5/16 spiggot are a bit much.

Mark

 

[Dukedog]

Plus 1. Use tha size hose that fits tha bib, 3/8 bib, 3/8 hose.