Briggs 10.5hp ohv backfiring through intake *EDIT*

cxbxr.3

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I got this mower second hand have no history on it other than it would not start, so I replaced the carburetor & spark plug changed the oil & it fired up,, problem is it coughs through the carb about ever 3-4 seconds & causes a slight engine speed surge when it does. I am checking valve clearance tomorrow but is there anything else I should look at ? it starts right up withing a second of the starter engaging & runs really good aside from the cough through the carb... The mower itself is a 2016 model so the engine appears to be the same.
 
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Tinkerer200

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Might check for air leaks around carb mount, spray some carb cleaner or WD40 around gasket areas. Maybe add a little choke manually and see if that clears it up. I am thinking lean mixture.

Walt Conner
 

bertsmobile1

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Might check for air leaks around carb mount, spray some carb cleaner or WD40 around gasket areas. Maybe add a little choke manually and see if that clears it up. I am thinking lean mixture.

Walt Conner

And use a trigger pack cause a stray spark will remodel your eyebrows.
 

EngineMan

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It could also be the inlet valve staying open a little bit.
 

cxbxr.3

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Valve clearance is spot on, tried another carb same thing happened,, plug is light brown so that seems good but odd. I'm going to get some gasket sealer & seal up the intake joints got a new oring coming in for the intake elbow at the head will report back tomorrow
 

EngineMan

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Valve clearance maybe spot on, but it may not be seating well....!
 
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