I got the R2R on my Novarossi 21-5K from Monty and it was GREAT, I still had to heat it, as you should anyway, But like said above, it was ready to race(R2R) when I got it, I ran 8 tanks thru it on the rich side and then leaned it a little and it's spot-on. It never died from being too rich like a new mill does, well worth the money to save the pain and suffering from breaking one in, can't wait for the "Balls to Fall" and see what it can really do!