1971 was the first year of the 70 series, featuring the G3 carburetor and came in 160cc & 125cc variants, It was replaced by the 80 series engine in the late 70's with the G4 Carburetor.
Victa 70 & 80 Series 1971-1983
Pictured Left is the G3 Carburetor Used on the 70 Series Engines, 70 Series engine can be modified to suit the later G4 Carburetor by replacing the barrel with an 80 Series version, Piston & Head should also be used to keep the matching parts with even wear together, New Gaskets should also be used.
Pictured Left is the G4 Carburetor used on the 80 series engines, This model had no primer bulb and was succeeded by the modern G4 Carburetor which is often referred to as the LM (Late Model) This has a primer bulb which also easier starting. Most Parts are Interchangeable between the G4 & LM Carburetors