If the kick starter is trying to blow off your foot when kick starting, something is drastically wrong. When this happens it is an indication that the ignition timing in the starting RPM range and or the moment of inertia of the crankshaft assembly is too small.
I have not used or tried to tune an engine with a HPI ignition. If it has a very small rotor, that could be part or all of the problem. If it has a rotor that has the same moment of inertia or higher than the OEM flywheel, the timing is at least 5 degrees too advanced in the starting RPM range.
If the HPI ignition is a programmable ignition I would retard the timing 5 deg in the 200 to 800 RPM range, leave the rest of the curve alone and see what happens. If the HPI has a universal timing curve similar to the basic very small rotor ignitions and other non programmable ignitions boxes, and the timing is adjusted by rotating the stator plate, rotor or reluctor plate, you may have a real dilemma. The choice is retarding the whole ignition curve so that the timing is correct at starting RPMs or correct at one RPM at the RPM of your choice.
My experience has not been good with ignitions timing curves that were not engineered for a particular engine package.
