Murray Briggs and Stratton 5HP Quantum Power Push-Mower blows white smoke

Craftsman Garage

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  • / Murray Briggs and Stratton 5HP Quantum Power Push-Mower blows white smoke
Murray Briggs and Stratton 5HP Quantum Power Push-Mower blows white smoke and barely dies down after startup, I think the carburetor setup is messed up but I can't find any sources showing the carburetor diagram. Any help is appreciated.
MODEL TYPE. CODE.
124702-3106-01 92042759
Lanerdude9
 

Rivets

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  • / Murray Briggs and Stratton 5HP Quantum Power Push-Mower blows white smoke
White smoke? The first thing I would check is the fuel in the tank. Fill a clear glass jar/with cover with about 2” of fuel from the tank. Put the cover on the jar and shake vigorously. If the fuel is not clear when you stop shaking you have water mixed with the fuel. Need to drain and flush the tank and replace with fresh fuel. This is what I taught my students.
Black smoke equals rich mixture.
Blue smoke equals oil mixture.
White smoke equals water mixture.
No smoke equals right mixture.
 

hlw49

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  • / Murray Briggs and Stratton 5HP Quantum Power Push-Mower blows white smoke
Have you checked the oil level in the engine. If over full can be contaminated with fuel and make it smoke.
 

Joed756

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  • / Murray Briggs and Stratton 5HP Quantum Power Push-Mower blows white smoke
Unburned fuel will make white smoke. A carburetor adjustment will likely cure it.
 

Craftsman Garage

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  • / Murray Briggs and Stratton 5HP Quantum Power Push-Mower blows white smoke
well, none of the above were the problem if you can believe it! before I was working on this, I put seafoam in the oil as directed, and looked up a few videos of what happens when you put seafoam in your oil, the white smoke was just carbon buildup burning off in the engine! after 5 minutes of running it, the pistons are nearly brand new, and there's no sign of carbon buildup anywhere in the engine, it doesn't smoke anymore and I just finished a long-awaited mowed lawn. feels good to do something HARDWORKING on a Saturday. thank you seafoam! :D
 

sgkent

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  • / Murray Briggs and Stratton 5HP Quantum Power Push-Mower blows white smoke
seafoam is awful stuff. IMHO more marketing than giddyup. I had some hard carbon in a Jeep engine that used to build up around the valves. One day I put pieces of it off the intake valves into small glass jars with different things that were supposed to soften and loosen carbon. The only stuff that worked was GM Top Cylinder cleaner. All those cleaners make a cloud of smoke as they burn. The carbon in most of the jars was still rock hard in 2 weeks when I thru it all out. The GM stuff worked overnight. Original formula cans are hard to find. Make a huge cloud of smoke when they are run thru an engine. BG44K is similar in how it works.
 

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grassmann

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  • / Murray Briggs and Stratton 5HP Quantum Power Push-Mower blows white smoke
sticky needle valve. put a shot of seafoam in the gas tank and fire it up. don't burn ethanol fuel. https://www.pure-gas.org/
 

peteco

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  • / Murray Briggs and Stratton 5HP Quantum Power Push-Mower blows white smoke
Sea foam?? If the engine was good why did you put seafoam in oil? Change oil.
 

Craftsman Garage

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  • / Murray Briggs and Stratton 5HP Quantum Power Push-Mower blows white smoke
Sea foam?? If the engine was good why did you put seafoam in oil? Change oil.
there was wear on the inside when I took it apart, and it definitely was harder to start when I didn't have seafoam, much easier to start and fires right up on the first pull
 
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