RE: Welcome to Club SAITO !
Good evening Ladies and Germs. I just got back from my little spearmint. Here's what I found with MY engines. First one; Saito FA45, Master Airscrew 11x6 wood, White Lightning fuel (10% nitro, 20% castor oil, no synthetic). Got engine warmed up and tweecked in a hair rich. I quickly opened the needle 1/4 turn. The engine slowed down almost immediately. Quickly set needle back 1/4 turn lean to original position. I had a stop watch ready to time the lag but the time lag in both directions was so short the watch wasn't needed. Second engine: Saito FA65. Master airscrew wood 13x6. White lightning fuel. Same routine. The lag between turning the needle valve a 1/4 turn in either direction was negligable.
I don't know why others take so long to speed up or slow down but at least two of mine don't. From what I remember of the others I have, they are the same.
At least that's what mine do. Wish I could record it so I could show all those who ain't gonna believe me. Wish I could upload pictures too but my puter must suck.