Engine was partially frozen, didn't take much to free it up. Crankcase was full of gas.
Engine runs, but it's backfiring through the carburetor. If I hold the choke at a certain point it seems to even out. I soaked/cleaned the carburetor and also tried another good carburetor.
Any thoughts?
Update. Checked flywheel key it's not broken. Switched out ignition coil and spark plug nothing changed.
As can burned valve, warped valve OR it is fairly common for the valve seats to come loose on these engines, hop in and out which is more common. Boy, a 12.5 hp 40 series B&S is an old booger.
