My 154 is bored at I think 30 over, not sure, cant remember what the guy I bought it from told me now. I have the Zenith carb on it, and it had a Prestolite distributor on it when I bought it. With the mower most of the way up, I can easily mow 2ft high dry weeds, and some higher if they are thin, in 2nd. The engine only has like maybe 200 hours on it since it was rebuilt.
I too would like to see more of the throttle set up KMO has.