Diaphragm Pump Replacement on Briggs & Stratton Pulsa Jet Carburettor

Does your older lawn mower surge? Is it hard to start?  Maybe that old ethanol gas has eaten away at the carburetor pump and diaphragm. It's pretty common this time of year when you first try to start that mower. Over the years of using gasoline with ethanol, it tends to distort and degrade the rubber parts that are not suited for ethanol. Watch this YouTube video to see how easy it is to replace those parts and get your mower running like new again.

Here's the OEM carb re-build kit: https://amzn.to/3ckMYcg or Stens aftermarket kit I used in the video: https://amzn.to/34Vhw08 Both kits work well.

If your tank is too far gone, you will need to transfer your older carburetor to a new tank. Here's OEM replacement tank: https://amzn.to/3fZ9yd0

Here's some other smaller parts you might need to replace as well:

Breather tube grommet: https://amzn.to/3fXbMcB O-ring for intake tube: https://amzn.to/3ggS36z Retainer for O-ring: https://amzn.to/3fXn8gR

A few things to keep in mind. 1) Be mindful of all the plastic and aluminum parts. Over-tightening screws can warp the carburetor manifold, and can strip out the treads on the tank.  2) It's easy to mis-place gaskets and rubber boots. The rubber elbow boot on the breather has a big side and a little side. The bigger side goes on the carburettor manifold, and the smaller end on the breather tube from the engine. Sometimes the air box gasket is stuck to the bottom of the air box. 3) Inspect all the parts you remove. These plastic and rubber parts degrade or flatten out over time and can lead to poor running conditions. Look for cracks, tears and breaks; or if that O-ring is flattened out and not longer looking like an "O"

If you do have any old gas in that can from last year, you can easily dispose of it in the fuel tank of your automobile. Your car has been designed with upgraded seals and rubber bits to withstand ethanol. A 1/2 gallon or so of stale gas mixed in with a mostly full tank of gasoline in your card is negligible. Your car won't miss a beat, even if there's a bit of moisture left in your gas can. 

There's several parts to get back on in certain order. I find it helpful to take notes, or sketch what goes where. I also take a lot of photos with my phone to help reconstruct what parts go back where. It's especially helpful if you need to order parts and have to wait a few days to get it back together. 

I hope these tips and tutorials can empower you with oracle like skills to make your small engines run smoothly and consistently.

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Mow Happy!

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Wear your safety glasses, or you'll put your eye out. Try on some gloves. Take off that spark plug boot. Clean your room. Open the windows, those fumes are nasty. Just 'cause I do it, don't think it's the end all, be all solution. There's plenty more ideas out there, I can't take responsibility if you slice off a few fingers after watching my videos. And don't just pour that toxic stuff down the sewer or in the ditch, dispose of waste responsibly. Just be safe, OK?