martysradios
Forum Newbie
Full tune up and valve lash is perfect. It backfires on occasion. Any thoughts?
d140 B&S model 44 popping backfiring thru exhaust
- Thread starter martysradios
- Start date
sgkent
Lawn Addict
you need to pit down enough that someone can answer your question. need the actual engine number and serial
In general there are many reasons it pops in the exhaust. It can be anything from an adjacent cylinder not firing, a misfire on one cylinder that sends a mixture of gas and air into the exhaust where another exhaust pulse ignites it, a sticking exhaust valve, too rich a mixture leave unburned fuel that outside air mixes with and sets off, a lean misfire, a rich misfire, improper timing, a lean mixture that burns so slow that the burn extends past the power stroke. bad spark plug can do it - someone buys their plugs online and unknown to them someone sold them a counterfeit.
In general there are many reasons it pops in the exhaust. It can be anything from an adjacent cylinder not firing, a misfire on one cylinder that sends a mixture of gas and air into the exhaust where another exhaust pulse ignites it, a sticking exhaust valve, too rich a mixture leave unburned fuel that outside air mixes with and sets off, a lean misfire, a rich misfire, improper timing, a lean mixture that burns so slow that the burn extends past the power stroke. bad spark plug can do it - someone buys their plugs online and unknown to them someone sold them a counterfeit.