The carburetors I show here are just about perfect for the 1" bore engines that I build. A-little story--It pays to shop around. I needed three carbs to replace ones I have stolen of old engines I have built to use on newer engines I have built. I checked on Amazon, and the price is $79 Canadian each. I checked with my local hobby shop and they said it was almost impossible to buy them now, but they could order two for $60 each. I then spoke with "Great Hobbies" and they said that these carbs were very hard to get now, but they could get me two for $49 each. I went back to my hobby shop here in Barrie and told them, and they dropped their price to $48 Canadian, each. It sure do help to shop around!!!