Might need a shim on the carb needle the part with the throttle cable attached. The shim raises the needle gives more gas. I think it may be stalling when the throttle is twisted. I bought the smallest washers I could find put them on a nail and held them against some sandpaper on a grinder that I use to sharpen a lawnmower blade. With the grinder running I held the nail with washers against the sandpaper 80 +- grit. The head of the nail keeps the washers there. Might want to hold the nail with vice grips, keep the fingers away. I used needle nose pliers to twist the plastic cap off the throttle piece once the wire is removed. Watch for flying parts, there is a spring in there. Place one washer on the needle and reinsert with the plastic piece and spring. Might be that once the choke turns off, more gas is needed.
