You hobby shop guy is wrong. What do you do with a 4 stroke that has the carb in the back????
ORIGINAL: Cjsworks
The guy at the hobby store told me when I bought mine that the outer diamater at the back of the spinner is not to extend above the lower edge of the carbs intake throught. He said larger than that would interfear with the carbs airflow and anything smaller is fine. Sounded good to me so I used a 2 1/4 on my .40 ASP.