Fuel hose size?

[Bubbamanboomer]

Im replacing all the fuel lines and installing a water seperator on my 1996 mercury 40hp 4cylinder 2 stroke. What size hose should be used? it looks like it should have 5/16 but some of what is there is 3/8 does this matter or should all the hoses be same size from tank to carbs? What size should it be?

 

[Bill Kilgore]

Re: Fuel hose size?

I am not a mechanic, nor an expert, but if the old hose diameter worked well, then I would replace it with the same size hose. That is also assuming no performance modifications were made to the motor.


Just my two cents

 

[Fuzzytbay]

Re: Fuel hose size?

I vote 3/8, on the fuel line, as for the carb lines, a quick check of a part number for them should give you the answer. Going by the old lines, (unless you are the only owner, and can vouch they are orginal) is not a good method. Some people think a hose is a hose, and diameter means nothing, so they will put on what ever they find.

 

[Bubbamanboomer]

Re: Fuel hose size?

I called mercury the gentlemen i spoke with said 5/16 on the fuel lines. I have a 3/8 going from tank to motor this shouldnt cause a issue i would think? i could see where too small a line would cause starvation. Any thought?

 

[sschefer]

Re: Fuel hose size?

I called mercury the gentlemen i spoke with said 5/16 on the fuel lines. I have a 3/8 going from tank to motor this shouldnt cause a issue i would think? i could see where too small a line would cause starvation. Any thought?

No problem at all. Many tanks use 3/8 to accomodate many sizes of motors. You mechanic is dead on the money. Your fitings should be 5/16 and that will feed plenty of fuel to your motor.