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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

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.

Have you checked the oil level in the engine. If over full can be contaminated with fuel and make it smoke.

Unburned fuel will make white smoke. A carburetor adjustment will likely cure it.

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!

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.

Joed756 said:

Unburned fuel will make white smoke. A carburetor adjustment will likely cure it.

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un burned fuel burns Black.

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/

Sea foam?? If the engine was good why did you put seafoam in oil? Change oil.

peteco said:

Sea foam?? If the engine was good why did you put seafoam in oil? Change oil.

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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

I really like sea foam I use it in every tank full of gas no matter what it is. It's a long story but I had a log splitter years ago that I couldn't get it to run right without the choke on a little no matter what I did to fix it. After adding sea foam after 2 tanks of gas it started running rich I cut the choke off and it's run great ever since. So who know?

troy-built said:

I really like sea foam I use it in every tank full of gas no matter what it is. It's a long story but I had a log splitter years ago that I couldn't get it to run right without the choke on a little no matter what I did to fix it. After adding sea foam after 2 tanks of gas it started running rich I cut the choke off and it's run great ever since. So who know?

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exactly my experience

sounds like the seafoam reps are back on the forums again. Terrible stuff, would not use it if my life depended on it.

sgkent said:

sounds like the seafoam reps are back on the forums again. Terrible stuff, would not use it if my life depended on it.

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NOPE not at all I'm a retired Corvette restorer of 35 years. If you don't like it don't use it, I don't make money off of it either way. All I know is it worked for me. Believe what you want.

Have a good one.

troy-built said:

NOPE not at all I'm a retired Corvette restorer of 35 years. If you don't like it don't use it, I don't make money off of it either way. All I know is it worked for me. Believe what you want.

Have a good one.

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surprised you'd use that over the genuine GM stuff that works better. GM Top Cyl cleaner.

sgkent said:

surprised you'd use that over the genuine GM stuff that works better. GM Top Cyl cleaner.

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I've used it before. I used it a lot when I worked at a Chevy dealer back in the early 80s. But it cost more than seafoam plus I like seafoam for other things that work for me. Have a good one

sgkent said:

surprised you'd use that over the genuine GM stuff that works better. GM Top Cyl cleaner.

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it doesnt work better bruh