Replacing a Briggs and Stratton primer bulb

Our primary lawnmower failed a couple days ago. The primer bulb that squirts raw gas into the carburetor got a small cut in in, so it could not hold pressure. The mower is a Wal Mart brand that has a Briggs and Stratton motor. I’ve another mower that doesn’t work for some reason, but it has the same primer bulb.

I went online and found that it was easy to pull the bulb out – you just had to remove a retaining clip. I looked all around the bulb, but couldn’t easily find a way to remove the retaining clip. The bulb looks like this:

The fuel primer for a Briggs and Stratton lawnmower motor

After looking at the darn thing for a half hour (and at the one on the other mower), I finally figured it out. You have to get the ring out from notches on the outside of the housing, instead of from inside the housing. Here is what the thing looks like from one side:

Primer Pump side view, Briggs and Stratton motor, from the back of the motor

To replace the bulb, take off the air filter (single long screw), and clean or replace the filter while you are at it.

Next, pull the red plastic cap off. I was able to with fingers alone. You need two small width flat bladed screwdrivers for the next part. Stick one of them into the back of the notch and lever the retaining clip forward, then go to the other side and use the other screwdriver to do the same thing on that side. The retaining clip will move forward, and you should be able to grab it and pull it out. Once that is out, the primer bulb will come straight out.

Put the new bulb in place, then replace the retaining clip and push it in. I used a deep socket that had a slightly smaller outside diameter than the primer bulb to push the retaining clip back in (make sure that it goes back in the same same way it came out – the flat part faces OUT). Put the air filter back on and you are done.

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9 Responses to “Replacing a Briggs and Stratton primer bulb”

  1. R Says:

    Engineers take fixing things as a personal challenge. The lawn mower/washing macine/dryer/car motor/dishwasher/lamp/etc will NOT defeat me! Bwahahahahaha…where’s the screwdrivier!

  2. jepancy Says:

    hi. great article!

  3. Larry the H Says:

    Well said, from a fellow engineer!!

  4. Big Danny Burns Says:

    My penis almost came off when I tried this….litterally, because I slipped when using the screwdriver and I almost got screwed myself!!!!!

  5. Dawn Blair Says:

    Thank you for sharing this. My primer bulb is cracked and worn. Every time I mow, the suction pulls it in and no more gas gets into the engine. It’s good to know it can be replaced — I’m not an engineer, but I do have the same philosophy. Now, where’s my screwdriver!

  6. eddie Says:

    where did you buy the replacement bulb mine just cracked and does not work any more

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