1/4" hose will work fine with your new electric fuel pump.

 

I ran into that when I used an electric pump--I found that "fresh" new 1/4" rubber fuel hose will go on the 5/16" nipples ,you just need to put some oil in the end of the hose and push firmly..old hardened up rubber hose wont,and you should get new hose that is ethanol rated anyways..

If you really feel its a must,you can buy the barb fittings with 1/4" hose barbs instead,but those may be hard to source locally and could cost $10+ ..

1/4" will flow plenty of fuel for any small engine,most vehicles with 4 cylinder engines used 1/4" fuel lines..

 

Thank you Tractor-Holic. I will need to "stretch" the line from the tank to accommodate the new fuel filter. I can reuse the fitting from the old mechanical pump for the output of the new pump at 1/4". All is good!

 

Fuel line is cheep, I would replace with new instead of stretching the old.

 

You can get a reducer coupling that is 5/16" on one end and 1/4" on the other too,if it will help you splice the new fuel hose to the original--they are available in brass or plastic,I trust brass more...personally I'd get rid of all the original rubber fuel hose,in case it is not ethanol rated...
I have made a few "hose size adapters",by sliding a short piece of 1/4" brake tubing into a 5/16" piece,and brazed or solder them together..