Tillotson Quick Jet Carb Needle Adjustment Tool

Hi I saw this on a video on youtube using a [Tillotson Quick Jet Carb Needle Adjustment Tool, as a way to be more accurate with tuning. Has anybody used it? If so do you think it’s worthwhile?

Never used it but I’ve seen it being used. I’d use it if I had one.

I have one and it’s useful to me. No guess work