Waste spark

Could we have problems with waste spark igniting some air-fuel mixture which wasn't burn in the power stroke?

Hi Victor,

You generally won't see anymore burning on the exhaust stroke from wastespark. In simple terms, the lack of clean air/oxygen in the cylinder is the biggest factor, since you have now gone from a cylinder full of air mixture with fuel particles to a cylinder full of exhaust gases this stops any combustion. Also with the exhaust valve now open, you have no cylinder pressure which is another key factor in the combustion process.