Mower blowing black smoke
Over View
You’ll find useful resources on this page, tips, links to tools, parts and supplies required to complete your repair.
Lawn mower carburetor problems are common. Black smoke is usually caused by a blocked air filter or sticking choke but a faulty carburetor is also on the list. The faulty carb supplies too much gas which causes black smoke and poor running.
Carburetors aren’t expensive or difficult to fit, if your carburetor is old, go ahead and swap it out. Wow, you’ll really notice the difference.
Before working on your mower be sure to remove the plug wire to prevent accidental starting, see “Repair Safety Video”.
Tools & Parts
To nail this procedure you may need the following tools, parts and supplies.
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 type of fastener sizes. Set includes spark plug sockets. 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 type of fastener sizes. Set includes spark plug sockets. Picture links to Amazon.com
Gas Line Clamp
Briggs & Stratton
This is a popular Hooai Carburettor fitted to walk behind mowers with Quantum engines, but check the engine codes listed. This is an Auto choke carburettor.
This carburettor has a fuel feed bolt in the base of the bowl, dirt in the bolt feed hole is a common issue. Picture links to Amazon.com
Briggs & Stratton
This is a after market replacement carburettor for the Briggs 4-7hp engines. This is the primer bulb style carburettor.
This carburettor has a fuel feed bolt in the base of the bowl, dirt in the bolt feed hole is a common issue.
It comes with a replacement air filter/primer bulb housing gasket. Without this gasket your primer bulb won't work. Picture links to Amazon.com
Briggs & Stratton
Honda GCV 160
This is a Hooai carburettor fitted to the Honda GCV160 engine only, not the GVC190. It comes with gaskets, plug, filter and fuel line.
Fitting isn't difficult, just a little tedious, take your time and some pictures of where the old gaskets are positioned and their orientation. Picture links to Amazon.com
Honda GCV 190
This is a Hipa GCV 190 carburettor fitted to the Honda GCV190 engine only, not the GVC160. It comes with gaskets, plug, filter and fuel line.
Fitting isn't difficult, just a little tedious, take your time and some pictures of where the old gaskets are positioned and their orientation. Picture links to Amazon.com
Drill/Screw Gun
John Cunningham is an Automotive Technician and writer on Lawnmowerfixed.com. I've been a mechanic for over twenty years, I use my knowledge and experience to write "How to" articles that help fellow gear-heads with all aspects of mechanical repairs, from lawn mowers to classic cars.