[jollyjumper]

if a motor has holes in it it will suck in lots of dust, i know from drifting on polished concrete with plastic tires.
was the same as your condition,very dusty.
i was using BL first ( novak) then brushed motors ( they rule for drifting imo).
the novak didnt suck in the dust, as its all closed.
but the brushed ones i had to clean after every 2 runs( bout a half hour or so)