A flooded engine is a pain in the jacksie, but this video will have you back mowing in jig time. It walks you through the whole process step by step, including drying out the cylinder, cleaning the spark plug, and starting a flooded mower quickly.
A flooded engine is a common issue. It often happens accidentally, too much choke applied or because the mower was turned on its side and gas flooded the cylinder. A wet or blocked air filter is another common cause of persistent flooding. If your engine floods regularly, it’s a sign of an underlying issue.
Typical root causes are bad spark plug, fouled plug, bad gas, faulty carburetor, bad armature. This video is dedicated to unflooding your mower quickly and getting you back mowing.
Before working on your mower be sure to remove the plug wire to prevent accidental starting, see “Repair Safety Video”.
You’ll find useful resources on this page, tips, links to tools, parts, and supplies required to complete your repair.
Tools & Parts
To nail this procedure you may need the following tools, parts, and supplies.
When cleaning your carburetor you’ll need this stuff. Gumming is a sticky substance that’s hard to shift. The carb cleaner will remove it, however, if your carb is really bad, save yourself some work, go ahead and buy a new carburetor. Picture links to Amazon.com.
Ratchet Tool Set
Before we can do anything, we’ll need tools. I’ve selected this set as I own some Craftsman tools and while I have worn some out, they did do a lot of work. So I expect this set will last the occasional user quite a long time. This set carries both metric and standard sockets and that’s important because some mowers will have both types of fastener sizes. Set includes spark plug sockets. Picture links to Amazon.com.
Plug Gapper Tool
This tool isn’t strictly necessary if you have a feeler gauge, but it’s a lot easier to handle. If you haven’t guessed. You use this tool to check the gap of your spark plug, a simple effective tool. Picture links to Amazon.com.
Gas & Oil Syphon
You’ll find this tool really useful if you need to drain the gas tank, and you will if the gas is stale. The siphon will remove it without fuss or mess and it can be used for extracting the oil too. Picture links to Amazon.com.
Gas Line Clamp
Some small engines will have a gas tap, which is really handy when removing the carburetor, stops gas flowing all over the shop. However most engines won’t have one, these useful clamps simply squeeze the fuel line and prevent a spill while you perform surgery. Picture links to Amazon.com.
Mix this with the gas when winterizing your small engine. Gas isn’t what it used to be, it goes stale, in some cases after just one month. Bad gas causes gumming and that’s a carburetor killer. A stabilizer will save you money and stress in the long run. Picture links to Amazon.com.
Briggs and Stratton refuel can. These guys got it right, I like it a lot, it offers press button control, no fuss no mess and no funnel required. Picture links to Amazon.com.
This tool is used to check both the spark plug and the coil for spark. Sure you can check the spark without the tool, but it’s not as good, the tool is designed to stress the whole ignition system. Picture links to Amazon.com.
The ABN 26 blade feeler gauge set is marked in SAE and metric. You’ll need this set to adjust valve lash and is useful when setting armature/coil air gap. You can also use it to gap spark plugs. Picture links to Amazon.com.
I use a Dewalt screw gun (also a drill) in the workshop to speed up the process of removing engine covers, carburetor bolts, Armature bolts, etc. It’s a brushless motor and as tough as nails, I drove over it a few times – still works great! Batteries are interchangeable and so if you have a Dewalt product already you won’t need the battery. Picture links to Amazon.com.
Wire Brush Kit
Stainless for heavy-duty and brass for and brass wire brush kit for heavy-duty and finer applications like electrical connections and softer metals. Picture links to Amazon.com.
- About the Author
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John Cunningham is an Automotive Technician and writer at Lawnmowerfixed.com.
He’s been a mechanic for over twenty-five years and shares his know-how and hands-on experience in our DIY repair guides.
Johns’s fluff-free How-to guides help homeowners fix lawnmowers, tractor mowers, chainsaws, leaf blowers, power washers, generators, snow blowers, and more.