Well, first off, clean off your carburetor if it has ANY dirt on it at all to see if there's anything that could be covered up. I thought my Carter YF had nothing on it and when I wiped the little film of dirt off of it there was the Carter YF plain as day, plus I found the model numbers and others that I'm not sure what they are. If you can't find anything you could probably post a picture and someone may be able to tell you.
