Complex sentence: The carburetor had only a simple butterfly valve, while two injection pumps supplied the cylinders with fuel: one handling four and one five cylinders-injection being into the manifold before they split into the two intake valves for each cylinder.
Split into simpler sentences: The carburetor had only a simple butterfly valve, while two injection pumps supplied the cylinders with fuel: one handling four and one five cylinders. Injection was into the manifold before they split into the two intake valves for each cylinder.