407577-0284-e1 spark plug gap - Briggs & Stratton Briggs Stratton Intek V - Twin Vertical Ohv Engine with Electric Start 22 Hp, 1" X 3 5/32" Shaft, ModelNo. 44K777 - 0027 - E1

Check the gap between flywheel and coil

.030

Standard gap is 0.5mm

did you try changing the coil and are the points gapped properly what about the condensor

did you gap spark plug to.028" ? may need to replace the valve cover gasket.

Gap setting for a Champion RC12YC spark plug is .030

The proper gap is ..030" Here is the Briggs application chart for L-Head engines like yours.
http://www.manddsmallengine.com/briggs/info/plug7.html

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&cad=rja&uact=8&ved=2ahUKEwiljOH95IH9AhUbk4kEHZiNBDsQFnoECAcQAQ&url=https%3A%2F%2Fwww.fixya.com%2Fsupport%2Ft7580947-air_gap&usg=AOvVaw2A3X0d4QjiGVVG4XNf9J0X

mine calls for .035

I have an E1 and I set my spark gaps from 0.7-0.8 millimetres. I also service an E3 and the gaps are set the same on that one as well