The mixing section has a gap in between

Do you mean the beater is not touching the bottom of the bowl? AS in there is a gap between the beater and the bottom of the bowl so it is not mixing all the ingriedients?
If you have a Tilt-head style mixer, you can adjust the beater/bowl clearance by turning out the adjusting screw. Place your bowl on the bowl screw cap, Place the flat beater on the agitator shaft and lower the head of the mixer so the beater is at the bottom of the bowl. There should be a 1/16" clearance between the bowl and the beater, if the beater is too close to the bowl turn in the adjusting screw, and if the beater is too far away turn out the adjusting screw. The adjusting screw can be located by tilting the head of the mixer back, and in the neck of the mixer you will see a flat head adjusting screw.
However if you have a bowl lift mixer and the bowl is too far from the mixer there are a few different way to fix that problem. If the bowl and beater are too far apart start by adjusting the adjustment screw. On this mixer the adjustment screw is under the head. Remove the bowl, and beater and lay the mixer on its back. You should be able to see under the head a screw sticking out, it does not have a head, but a little slot in the screw, use a flat head screw and adjust the beat 1/4 turn. Put the beater and bowl back on and test mixer to see if it the beater has a 1/16" clearance. If it doesn't adjust the screw and 1/4 turn. If after adjusting the screw the beater and bowl still have too much clearance use a mallet and tap both sides of the yoke arm up evenly until 1/16" beater to bowl clearance is met.
You can use the same dime test in the bowl to make sure you have the correct 1/16" measurement for the beater/bowl distance.
Thank you,
Colleen
MendingShed.com
800-339-9297