Scooterotica

I'm running a AQ266 atomiser a D22 needle with the clip in position 2. I have tried running a filter but the problem gets a lot worse.

You're very rich on the main. You'll need to be around the 102 -105 mark is my guess. The rest of the carb is near identical to the set up I use on GT186 kits with the exception of the main jet. Piston ported kits tend to use a larger main than reed valves. PHBL25 carbs are a very good for the money, parts are common, sensibly priced and they perform well. Your jet size is usually smaller if you run an air filter so make sure you set up accordingly.

There are plenty of pattern carbs that belong in the bin but not the PHBL it is a good quality product. Granted, VHSH and other flat slides give better performance but they also cost a lot more, don't blame the carb in this case.

Thanks for the advice.