[autoavia]

I forgot that Fly have a thing about mounting the motor where the original engine would have been. Generally speaking slot cars with front mounted motors don't work well although again magnets hide many of the problems. You can't beat the weight of a motor over the rear wheels for giving traction when running non mag. Certainly beats the understeer that front mounted motors seem to cause.
 I seem to remember that there was a time when split pinions were quite common on Fly cars and older stock often has tyres which have gone hard and reacted with the plastic plinth.
 Fly make great slot car bodies but their running gear has never been good for running non mag on wood although glueing the axle bearings into the pod, glueing  the motor in and glueing the motor pod to the chassis does stop a lot of the hop.