Late sixties to early seventies full cranks sound more energetic compared to later ones, no doubt about it.
Your average plastic carburettor domestic mower is a different animal over an average impulse starter mower. I have memories of our neighbours early 70s Corvette with metal float G3 and impulse start and it sounded sporty compared to our 1977 Waltons mower which had the same base and catcher BTW.
Although there was a slightly earlier Waltons mower I used with same base but with metal engine cover and G4 carby, which sounded as good as the aforementioned Corvette. Maybe they had the same barrel moulding. I heard Victa used four moulds at a time during 160' full crank engine production with some being minutely better than the others.
