ArtsAutosBooksBusinessEducationEntertainmentFamilyFashionFoodGamesGenderHealthHolidaysHomeHubPagesPersonal FinancePetsPoliticsReligionSportsTechnologyTravel

DIY - Replace Primer Bulb

Updated on July 4, 2014

How to Replace Primer Bulbs - DIY

I couldn't count the number of Primer Bulbs that I've had go bad over the years. Since you're reading this, you're probably dealing with a bad one right now. Fortunately, replacing a primer bulb is neither expensive nor difficult for the DIYer - read on for details.




We're replacing the reddish bulb with the hole in it. The blue items are the choke lever and the chain trigger. The black is the tool's case and handle. The brown flakes just show that I don't clean my tools as often as I should.

broken Primer Bulb
broken Primer Bulb

Primer Bulb Not Working?

Primer Bulb Problems

What was once a pin hole grew and grew. It's definitely time for a replacement.

This tool pictured is a Homelite chainsaw but the procedure is the same for any small engine application: weed whackers, edgers, small mowers, even some outboard motors.

Primer Bulb
Primer Bulb

How To Replace Primer Bulb

Getting Started

First, determine if your primer bulb is a complete assembly unit or a bulb being held in place by a metal plate or collar. If it's a bulb and plate, page down to the video directions.

If it's an assembly unit:

  • Pull the bulb assembly out from the tool's casing.

  • Clean away any sawdust, grass, dirt, etcetera using a rag or compressed air. You don't want any foreign matter to get into the fuel lines.

Replacing Primer Bulb
Replacing Primer Bulb

How To Replace Primer Bulb

  • Disconnect the fuel lines from the nipples on the back of the primer assembly by gently pulling with Needle Nose Pliers. Here I've attached a paper Spring Clip to the first fuel line so that it doesn't pull back into the case.

Homelite Primer Bulb Replacement
Homelite Primer Bulb Replacement

How To Replace Primer Bulb

  • The disconnected primer bulb assembly and clips on both fuel lines.

Primer Bulbs
Primer Bulbs

How To Replace Primer Bulb

  • Using the pliers, gently connect the fuel lines to the nipples on the back of the new bulb assembly.

  • Carefully insert the new assembly into the hole.

  • Pump the bulb to test.

You're Done.



If you forgot which line connects to which nipple:

- Cover one of the nipples with your thumb and press the bulb. The nipple that "blows" should connect to the fuel line that goes to the carburetor (the one with the white line). The nipple that "sucks" should connect with the fuel line that goes to the fuel tank.

- Or, just connect the fuel line that has the white line to the longer nipple and you'll probably be correct.

How To Replace Primer Bulb Video

This procedure is demonstrated on a Homelite but it is applicable to many small-engine manufacturers: Honda, Toro, Husqvarna, Briggs and Stratton, Weed Eater, Dewalt, Generac, Troy Bilt, Stihl, Ryobi, Poulan, Murray, etc.

Tell Me How Your DIY Project Worked Out. - the Obligatory Comment Box

    0 of 8192 characters used
    Post Comment

    • profile image

      anonymous 4 years ago

      @anonymous: Make sure your fuel and return lines are correct

    • profile image

      anonymous 5 years ago

      Erniep, I had fitted the gasket on the wrong side of the carburetter block, I have corrected that and the bulb works fine now but the strimmer will not start, any ideas

    • profile image

      anonymous 5 years ago

      Not good I changed the primer bulb on a 25cc grass strimmer puchased from B&Q , the bulb when sqeezed does not return to its former shape so it is not working, I suspect that I may not have put the gasket back corectly can anyone help

    • profile image

      anonymous 6 years ago

      I haven't had to replace a primer bulb but now I am ready if I every have to!