Hi. I've just purchased a lunchbox kit for my sons xmas present, I've had a look through the box and all is well though I'm starting to worry the silver can motor may still be a little fast for him at 5 yrs old, he has driven my edge before but i worry about its break ability. I bought the lunchbox as they look tough in comparison but I'd worry even less if it was tuned down for a while for him to get to grips with it. Should i buy a higher turn motor or lower toothed pinion? Or both?