I think I found my vibration problem

hey i've been reading this though , and you said that the vibration got better '' as in went away '' at higher rpm , well was it floored . had a partner ''help with a 440 once '' , he under cut the counter weights on the crank , quote '' to make it rev'' he said . it did , but it vibrated like crazy , untill you floor it . it would run up to max r's , with no issues . just putting it out there . did the guy have a lath ?

no he didn't have a lathe. I also know he didn't have it sent out and balanced.