i like it. use what you have!
and lead acid is much safer than some of the guys i see with R/c packs taped to their frame. lead acid has almost no chance blowing your balls off if you stall!

COm: Bryan : You do need fuses so that you dont ignite the hydrogen that is released from the lead acid battery if and when the starter shorts out.

So, ohms law is helpful here. If the starter motor consumes 1000 watts power then you need an 83 amp in between your throttle switch (solenoid) and another one of the same current value in between the swith and the starter motor. 

Com : I bet you could go even faster if you hooked one end of a pair of battery cables to the battery and clip the other banana clips to your balls. Be sure to wet them first.