How to Replace the Primer and Hose Assembly on a Ryobi Trimmer

Primer past its prime? It's time to face the fix. Whether you are a legendary landscaper or a weekend weed whacker, eReplacementParts.com provides the parts, procedures and facts you need to fearlessly fix what fails you.

The primer assembly pumps fresh fuel into the trimmer's carburetor, which makes the engine easier to start. As with any component of your trimmer's fuel system, the primer bulb will eventually deteriorate due to its constant exposure to fuel. Fortunately, replacing the primer assembly is very easy to do.

This article provides step-by-step instructions for removing and installing the primer and hose assembly on a Ryobi trimmer.

Let's get started.

  REMOVING THE PRIMER [top] 1. Remove the rear cover.

Remove the (4) screws from the rear cover.

Remove the rear cover from the engine.

  2. Detach the carburetor.

Drain any excess fuel from the fuel tank prior to servicing the carburetor or the fuel lines.

Remove the (2) screws from the carburetor assembly.

Remove the choke plate and choke assembly from the carburetor.

Disconnect the throttle cable from the carburetor (this is accomplished using a lift-and-twist motion).

  3. Remove the fuel lines from the primer assembly.

Note that the connection inlets/outlets on the back of the primer assembly are different lengths. It can be helpful to draw a diagram (or take a photo) illustrating the existing configuration before removing the fuel lines.

On the model shown in this article, the fuel return line (between the primer and the fuel tank) attaches to the longer stem of the primer assembly. The line between the carburetor and the primer attaches to the shorter stem of the primer assembly.

Disconnect the (2) fuel lines from the back of the primer assembly. These lines should pull away from the assembly relatively easily (by hand); however, long-nosed pliers may be used as necessary to remove the lines.

  4. Remove the primer assembly.

The primer assembly is held in place by two (plastic) locking tabs. Use long-nosed pliers to compress these tabs (which will release the primer assembly from the base).

Remove the primer assembly from the mounting base (slide it toward the back of the trimmer; away from the trimmer head).

  INSTALLING THE NEW PRIMER [top] 5. Install the new primer assembly.

Align the tab on the new primer assembly (beneath the short inlet) with the slot on the mounting base.

Press/snap the new primer assembly into the mounting base.

  INSTALLING THE FUEL LINES [top] 6. Install the fuel lines.

The primer kit comes with a new piece of fuel line. To remove the old fuel line, pull the line (which was disconnected earlier) through the carburetor mounting plate (toward the carburetor).

Disconnect the old fuel line from the carburetor. This line should pull away from the carburetor relatively easily (by hand); however, long-nosed pliers may be used as necessary to remove the line.

Install the new fuel line onto the carburetor.

Pass the new fuel line through the hole in the carburetor mounting assembly.

Connect the new fuel line to the primer assembly (the line from the carburetor attaches to the SHORT inlet on the primer).

Reconnect the fuel return line to the primer assembly (the fuel return line attaches to the LONG inlet on the primer).

  REASSEMBLING THE UNIT [top] 7. Reinstall the carburetor.

Install the carburetor gasket (as necessary).

Install the throttle cable onto the throttle linkage of the carburetor.

Install the carburetor mounting screws onto the choke plate and lever.

Secure the carburetor (and choke plate) to the engine with the (2) screws. Note that the choke lever and the wavy washer must be properly aligned before tightening the upper screw.

  8. Reinstall the rear cover.

Reinstall the rear cover onto the engine.

Secure the rear cover with the (4) screws.

You don't have to leverage your savings to level your lawns. As you just learned, repairing your own equipment is easy when you follow our step-by-step guides. Not only did you restore trimmer functionality at a fraction of the cost of replacement; you have taken the edge off of future repairs, wherever you may find them.

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