How about a secondary starter using spring power, possibly pumped up with a hydraulic foot petal. Of course it would have to be freewheel somehow.
Now if your battery is dead, pump that extra pedal 4-5 times, and hit the start lever, and it cranke the motor 4-5 times.
Ok, that idea doesn't work for some reason, here's another... Use the pedal and a spring to generate the amps to turn the starter. Pump it up...turn the key...and hit the release lever, when it starts, let off the key like normal.