F725 big white smoke cloud

[Bama66]

Is there any way the fuel pump could be causing our problem? It is mounted on the side with of engine with actuation lever in oil pan.

 

[Biscuit Barrel]

when you get the white bomb and shut it off, if you restart it do you get the white bomb again? If NO, then I don't know how "gas in oil" cleared itself up.

I've had the white bomb myself and it was leaky carb with no fuel shutoff that was leaking while not in use, then when started white bomb always AND oil level was well above the full mark. it doesn't sound like this was your problem. If engines runs OK for periods, there is no gas in the crankcase - if there was, you would get WB all the time.

Therefore, if it is WB from "gas in oil", then it has to be coming from the carb in 2 second bursts. But could that fuel dumping produce the WB as if gas in oil?

Thinking... why white bomb when gas in oil? Has to be oil on the cylinder walls gets burned producing WB. So if WB occurs when running, huge amount of gas must be dumped from carb. (Can't be the fuel pump because it couldn't leak the amount of fuel into the oil to produce that washing on the cylinder walls.)​

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Thinking... there is a loss of power. This could be like the engine was choked due to a huge amount of fuel coming from the carb. Does the loss of power seem like choking? If it runs good and you choke it, do you get the WB?

Thinking... the amount of fuel that dumps out of the needle/seat when float low is not a torrent, it's more like a dribble. But if the bowl is full and the float is closing the needle, if a leak, it has to be much less which doesn't quite explain the WB even if full needle discharge would be enough fuel flow to create WB.

Is there a possibility the float is sticking? did WB occur when you ran over something that shook the engine OR hit a heavy patch of grass that put big load on engine?​

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STICKING RING: Automotive Engine with bad rings will WB when under full load. But the 2 second duration is not quite consistent with this cause, however could be something small engines do.

Maybe my thoughts will give someone an eureka moment?

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[Forest#2]

What model, type and code of engine?
WB can also appear as burned oil when viewed in sunlight instead of being blue.

 

[Biscuit Barrel]

What model, type and code of engine?
WB can also appear as burned oil when viewed in sunlight instead of being blue.

Could you elaborate: is it White vs Blue? perhaps Rings vs Gas in Oil (which is which)?

 

[The Maintenance Guy]

Just serviced my engine oil & filter, transmission fluid and filters, air and fuel filters. While mowing a huge cloud of white smoke came out of the exhaust while I simultaneously noticed a brief decrease in engine speed. Lasted about 2 seconds. i immediately killed it and checked all fluid levels and looked for any leaks. All was fine. I started mowing again and this occured twice more before I shut down for the day. Any ideas what’s going on? TIA!
Johm

I had that happen once when I inadvertently overfilled the crankcase when changing the oil. It was OK until I went on a slope sideways then...wow! I took some oil out with a suction gun and all was well.

 

[rutbuster1]

There is a fuel cutoff. I have never used it.

It's best to use it if you have it. It'll save you a lot of headaches in the future. Your symptoms seem to be that the needle seat isn't sealing gas from going through the carburetor. Using the fuel cutoff will cut off the fuel supply and keep it from flooding. Another thing too. When storing the mower for long periods, while it's running, cut off the fuel supply and let it run till it quits. This will help save the carburetor from fuels mixed with ethanol.

 

[Bama66]

There are some great things for me to try, especially fuel cutoff. As I said I’ve never used it but as said I probably should have and this problem wouldn’t exist. I’ve got to tell everyone how much response and how quick it was made is GREATLY appreciated. I’ve always had great help from this group. Again THANKS,

 

[Biscuit Barrel]

There are some great things for me to try, especially fuel cutoff. As I said I’ve never used it but as said I probably should have and this problem wouldn’t exist. I’ve got to tell everyone how much response and how quick it was made is GREATLY appreciated. I’ve always had great help from this group. Again THANKS,

The fuel cutoff will guard against storage leakage which fills up the crankcase. When that happens you have WB all the time. You don't have that problem.

The comment about cutting on a slope is a good one: is there any pattern to when it happens?

 

[Bama66]

Smoke has a white color.
checking on engine numbers

 

[Bama66]

Just serviced my engine oil & filter, transmission fluid and filters, air and fuel filters. While mowing a huge cloud of white smoke came out of the exhaust while I simultaneously noticed a brief decrease in engine speed. Lasted about 2 seconds. i immediately killed it and checked all fluid levels and looked for any leaks. All was fine. I started mowing again and this occured twice more before I shut down for the day. Any ideas what’s going on? TIA!
Johm

We took the bowl off, sprayed carb clearner from top and bottom, flicked the float a few times, put it back together and changed oil twice and everything seems fine now. Thanks everyone for your suggestions!