I don't build nascar engines and I don't wanna hyjack this thread, I'll just say this.
If a carbs mixture was spot on for the weather but was too small, cfm wise, it would be come a rev limiter but not the sense of popping and or sputtering, instead it just wouldn't ''rev'' anymore.
google Restrictor plate racing.
no biggy,
Just trying to give an idea of the diff between running too lean and running out of air. btw fuel pressure is another place to look. :smile: