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I have a Briggs and Stratton 4-cycle, OHV, self-propelled mower. It is several years old, we just got it from a friend. It worked the first few times we tried, then just woudn’t start. I changed the spark plug and air filter. Still nothing. Then I pulled out the spark plug and put a little bit of gas in the well. It started and ran like a champ for an hour while I finished the lawn. I believe this is a carburetor problem, but don’t know for sure and I am a novice repair guy who wants to learn how to do all this myself. What do I need to clean/fix/replace, and how do I do it? Thanks so much.

First off, I’d clean the carburetor. Take the bowl on the bottom of the carb off. You will see a float and a needle valve. Make sure the float moves and that the needle valve functions properly. Clean your gas line from the tank to the carb as well as make sure that your gas cap is vented, there are either a few holes in it or a washer underneath the cap. If it is not vented you will get a vacuum and fuel will not flow. Good Luck and I hope this helps.

i’m like you, in that i wasn’t born with a wrench in my pocket, but i wanted to know how to take care of things on my own. with average aptitude and a few tools, willingness to read and learn, and the internet, and you’re on your way. for me, no matter if it’s a washer or dryer, stove or frig, mower or truck, etc., it always starts with a model number. use it to do a search and you find diagrams and parts as well as troubleshooting guides and repair videos. one thing i can tell you about small engines (these days) is that the carbs are crap. 85-90% of the problems i run into with small engines is carb related. your problem is very likely solved with carburetor service ( but don’t overlook first checking for other obvious problems, like a cracked primer bulb, etc.). the answer provided previously is very decent, but assumes you know the language and/or are familiar with the components, which you may or may not be. understanding how a carburetor works or how to service one is not rocket science, but you’ll benefit greatly by reading up on it, first. if you do get into such things, here’s a couple of thoughts- start by clearing the clippings, grime and grease, etc., from the mower, so these potential contaminates are eliminated. take a picture of the way things are assembled before you start, and at various points along the way, so you can be sure the way things are put back together. also, when you begin to take things apart, do so carefully, as it’s easy for these small parts (including springs) to get away from you and get lost, or at least hard to find. have some bench-top area with a couple of trays (for parts), carb cleaner, degreasing solvent, and some shop rags. you’ll be needing pliers, wrenches, sockets and screwdrivers, and an assortment of small gauge wires. having a compressor and air nozzle to be able to blow things out or off helps too. finally, when cleaning the carb, bear in mind that in addition to other carb service aspects, the tiny ports the fuel flows thru are easily plugged with some kind of debris or deposit. use carb cleaner and spray all ports (be sure to protect your eyes and hands), and use the appropriate size wire to clear each port, then spray again, and (if you have compressed air) blow out. make sure each and every component is clean, and re-assemble things exactly as designed. hope you find your problem and in the process get to learn some things, too. Good Luck!!

Spark plug well is flooding with gas won’t start . What can I do to correct this?

If the mower has been sitting for awhile, consider the gas may be too old or contaminated with water.

If you clean the carb, take the small brass piece (jet) out and poke the little holes with a paper clip to clean them. Make sure they are clear either by looking with a light or blowing through them. Poke the areas where the jet screws into. I use carb cleaner to squirt those ports and look for cleaner to then squirt into the carb throttle bore to ensure they are indeed clear.If the spark plug is dark and shiny, it is probably fouled. Either sand blast the electrode end until the insulator porcelain is fairly white or just replace it. If you have an old automotive spark plug laying around, don’t try to use that in your small engine. They are too long and even though they might not hit the piston, they will be in the wrong position to ignite the fuel. I know…..I tried them. Spark plug sand blasters are around $15……but you also need an air compressor.Take all air cleaner parts off until you can get to the carb so that you can see the buttlerfly flap move. Use the equivalent of an eyedropper to squirt some gas in the throttle bore. If you can crank it now and get some pops then it will eventually start. If it does start and keeps running, the carb cleaning and spark plug cleaning did the job. If it starts but won’t keep running even after several squirts of gas and restarting, the carb ports are either still clogged or the fuel line is clogged. Also, put enough gas in the tank to ensure gas is actually getting to the carb.An additional note. I was working on an Intek engine that wouldn’t respond to the primer bulb. I would push the bulb and smell no gas and the engine would not start. I took the assembly with the primer bulb off and noticed that the hole in the plastic piece with the primer bulb didn’t match up with the hole in the carb. The primer bulb passage was in effect closed off. I ended up making a special gasket with a passage for the hole in the plastic air cleaner piece to send air from the primer bulb to the hole in the carb and now it starts easily. This one is a mystery to me.