How to Install Fuel Line – Tricks of the Trade

Sometimes you have to install new fuel line on your lawn equipment. Like every part on your outdoor power equipment, fuel line wears out.

Exposure to the elements like the sun and that devil ethanol will destroy your fuel line over time. It is also possible, your fuel line has degraded due to age. Nothing is going to last forever. Except that bag of uranium you threw out last week.

Whatever the reason at some point you are going to need new fuel line in your lawn equipment.

For a small engine repair shop like ours, replacing fuel line is almost a daily task.

Whether you are replacing fuel line in your chainsaw, lawn trimmer, leaf blower or lawn mower, knowing the proper steps and tricks will make it an easy task.

REPLACING FUEL LINE ON FOUR CYCLE ENGINES:

On four cycle engines, you are usually looking at a 6 to 12 inch piece of 1/4″ black braided fuel line.

PARTS REQUIRED:

  1. Four cycle fuel line.
  2. Fuel hose clamps.

OPTIONAL PARTS REQUIRED:

  1. Inline Fuel Filter.
  2. Inline Fuel Shut-Off Valve.

TOOLS REQUIRED:

  1. Pair of pliers.
  2. Utility knife or scissors.

STEPS TO REPLACING FOUR-CYCLE FUEL LINE:

  1. Disconnect the spark plug. This is a simple safety precaution. It prevents your engine from accidentally being started while your fingers and toes are in places they shouldn’t be. Do it, don’t do it, it is really up to you. Just to complain to me when people start calling you 3 finger Bob.
  2. Remove the old fuel line clamps. Grab the tabs on the fuel line clamp with a pair of pliers and squeeze. Then slide the fuel hose clamps off the fuel line where it is sitting on the connector.
  3. Remove the old fuel line. Pull the old fuel line off the connector. Depending on the age of your fuel line this might take some serious work. If it will not come off, you may have to slice the fuel line using a utility knife.
  4. Using a utility knife or scissors cut the new fuel line to length. You can use your old fuel line as a guide.
  5. Slide the old fuel hose clamps on the fuel line. You might want to consider replacing the fuel line clamps while you are at it. They wear out over time too.
  6. Push the new fuel line onto the connectors.
  7. Install the fuel line clamps. Grab the tabs on the fuel line clamp with a pair of pliers and squeeze to release the tension. Then slide the clamps up and onto the fuel line where the connectors are.
  8. Depending on the model of your small engine you may have an inline fuel shut off valve. If you do, this is the right time to replace it. If you do not, consider adding one. See our article on fuel solenoids for reasons why it would be a good idea.
  9. Also, depending on the model of your small engine you may have an inline fuel filter. If you do, this is the right time to replace it too. If you do not, consider adding one. Fuel filters are a cheap way to keep dirt from getting into your carburetor.
  10. Inline fuel shut-off valves and fuel filters are also installed using fuel line clamps. Grab the tabs with a pair of pliers and squeeze to release the tension. Then slide the connector on or off.

In about 10 minutes, you will have installed new fuel line, new fuel filter and new fuel shut-off valve on your small engine. After that you will be good to go.

REPLACING FUEL LINE ON TWO CYCLE ENGINES:

Replacing fuel line on two cycle engines presents a whole new set of challenges. I am referring to equipment like chainsaws, lawn trimmers, leaf blowers and other hand-held equipment.

For one, they are very small. (Save the jokes.)

Installing thin limp fuel line into the tiny holes of the fuel tank grommet might make you want to chuck the dang thing across the garage. If it does, head over to LawnMowerPros and pick up a new one.

If you are commited to replacing your two cycle fuel line instead of replacing it keep reading.

We thought it would be a good idea to teach you a couple of tricks we use around the shop when replacing fuel line on 2-cycle engines. This will make the task a little easier and maybe keep you from pulling your hair out.

But before we get to the most amazing small engine fuel line tips you will find on the internet lets go over the basic steps to replacing 2-cycle fuel line.

PARTS REQUIRED:

  1. 2-cycle fuel line.
  2. 2-cycle fuel tank vent.
  3. 2-cycle fuel filter.
  4. 2-cycle fuel tank grommet.

TOOLS REQUIRED:

  1. Needle nose pliers.
  2. Flat blade screwdriver.
  3. Utility knife or scissors.
  4. Small Wire Hook. You can make your own using an old wire coat hanger or wire you have sitting around.

OPTIONAL TOOLS:

  1. Lubricant. 2-cycle oil mix is the only lubricant you should use. Save your WD-40 for throwing in the trash because that’s the only thing it’s good for.

STEPS TO REPLACING TWO-CYCLE FUEL LINE:

  1. Disconnect the spark plug. This is simple safety precaution. See above for why your new nickname might be 3 finger Bob.
  2. Disconnect the fuel lines from the carburetor.
  3. Remove the fuel tank. This is an optional step but will make the job a lot easier. Usually it is 3 or 4 screws. Note: This does not apply on most 2-cycle chainsaws.
  4. Remove the fuel tank cap.
  5. Using your wire hook reach into the fuel tank though the fuel tank neck and grab the fuel tank vent and the fuel filter.
  6. Pull the fuel tank vent and fuel filter out through the fuel tank fill hole, then using a utility knife or scissors snip them off.
  7. Pull the old fuel line out of the fuel tank grommet.
  8. Using a flat blade screwdriver remove the fuel tank grommet.
  9. Cut the new fuel lines to length using your utility knife or scissors. You can use the old fuel lines to determine the correct length to cut them.
  10. Install the new fuel line into the new fuel tank grommet.
  11. Reinstall the fuel tank grommet into the fuel tank.
  12. Using your wire hook, reach into the fuel tank through the fuel tank neck and grab the fuel lines.
  13. Install the new fuel filter and new fuel tank vent.
  14. Push the fuel filter and fuel tank vent back into the fuel tank.
  15. Reinstall the fuel tank cap.
  16. Reinstall the fuel tank on your piece of equipment.
  17. Connect the fuel lines to the carburetor.

And DONE!

Now it is time for our super amazing small engine fuel line installation tips and tricks.

TIP ONE:

USE THE RIGHT TOOL FOR THE JOB.

For replacing 2-cycle fuel line, the following tools are super helpful:


Standard Pliers or Needle Nose Pliers.

Utility knife or scissors.

Small metal hook.

Shop rags or an old t-shirt. If you have decided to use your old Metallica T-Shirt from the 1983 tour please send it to me instead. If you do, I’ll send you a 6-pack of shop towels.

Bolt or Screw removal tools (Misc)

TIP TWO:

CUT THE NEW FUEL LINE INTO A POINT.

Using your scissors or utility knife, cut the end of the fuel line into a point prior to feeding it through the fuel tank grommet.

TIP THREE:

LUBE IT UP.

Wet the line with a little lubricant prior to installing into the fuel tank grommet. Usually, cutting the fuel line in a point or at a diagonal will make the fuel line go into the grommet easily. But if not, use a tiny bit of 2-cycle oil mix and the fuel line should slide right in.

TIP FOUR:

GIVE IT A TWIST.

Insert the pointed fuel line into the hole, then twist it with a “screwing” motion. It may take a little time, but it will work.


thread it in

Once you can reach the line with the metal hook, or coat hanger, grab onto it, pull it through the fuel tank neck and clip the end flat.

TIP FIVE:

GET OUR STUFF WIRED TIGHT!

Sometimes the position of the fuel tank prevents you from getting your fingers in there close enough to actually push the line into the hole.

This is not a problem.

COPPER WIRE

Get a piece of strong but malleable 14 or 16 gauge copper wire. About 6 inches should do. If there is conduit or insulation on the line, strip the end of the wire.


wire to thread it

Feed the wire into the tank through the fuel line hole and out the fuel tank neck.

wire to thread IV

Insert the wire through the end of the fuel line. Loop and twist.

wire to thread it II

Using the wire, carefully pull the fuel line through the hole and into the tank.

If it is stubborn, coat the fuel line with a little 2-cycle oil. See above.

wire to thread it III

Pull the fuel line on through, disconnect the wire and snip the end of the fuel line flat.

TIP SIX:

HOW TO GET THE HOOK UP.

A simple metal hook will come in very handy for fishing out old fuel line, new fuel line or debris still in the tank. We use one that we fashioned from an old metal coat hanger. Sometimes you just have to do whatever works.


metal hook

And that is the end of our small engine fuel line installation steps and tricks.

If you have any sweet little shop tricks on how you get past your small engine repair problems please send them to us. We would love to share them on this blog.

Until next time…

-Jack

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Jack Hayes

Jack Hayes

Jack Hayes is the Head of Internet Marketing at LawnMowerPros and the editor of this blog. You can often find him creating featured articles, DIY guides, custom graphics and much more.