Xray328,
That engine's carb has 2 needles on it. The big needle is for the high speed adjustment. These engine use an air bleed adjustment for the low speed adjustment. If you look at the front of the carb you will see a small hole up towards the top of the carb. This hole is the air bleed low end. There is a scree that extends from the hole out to the side of the carb. This screw is the low end adjustment. Refer to attached picture.

One note, be very easy when making adjustments on the low end. A little turn goes a long way to make adjustments. Turn it as little as possible for each adjustment.

Hope this helps

Ken