Gas line Size

[San Chan]

Hello ALL,

I am about to install my water separator and don't know which Gas line to use. 1st of all, the line on my 90HP Mercury (4s), the wording is no longer there so I don't know if its 5/16 or 3/8. I already have 2 Moeller Hose Barbs thats 1/4NPT x 3/8 thinking that bigger should be better just in case the outboard stave for gas......so my questions are;

1) just in case if the one on my outboard is 5/16 and I use a 3/8 (OR THE OTHER WAY AROUND) to install the Separator, you guys see any problem/s?

2) if I can use either one, which one will be better?

3) any issue/s if I have it between the Primer Bulb and Outboard? Or is its has to be before the Primer Bulb ?



Thoughts


Thx

[Hot Runr Guy]

I believe your Mercury fuel line is 8mm, or 5/16". If you can fit it on your 3/8" barbs, then you should have a larger flow diamter thru the barb.

I've got my seperator between the tank and the bulb, or to put it another way, the primer bulb is between the seperator and the motor.
HRG

[yarcraft91]

I expect HRG is right- your fuel line is 5/16" and that isn't going to starve your outboard. A 3/8" line is big enough to feed my 120 2-stroke, which probably burns fuel 3 times as fast as your 90 4-stroke. Larger fittings won't hurt anything on your fuel system, as long as the hose barbs and hoses are matched in size.

[San Chan]

Thank you, I tried but hard to fit it in and I can't use a lighter to soften it so......... gettting a right size one.