ok matt,the bike does not have power bands ,power bands are just the term for the peak rev range on a highly tuned 2 stroke engine which is not what you have im afraid the ke 100 is a very underpowered trail bike from new.i would suggest a new spark plug and also to strip the carburettor down and clean all the jets out with carb cleaner and a high presssure air jet.the flat battery will not affect the running of the bike at all as the primary ignition coil is totally seperate from th charging sysem for the battery although i would suggest fitting a new battery to it if the bike is used on the road as all the electrical items on the bike i.e horn indicator brake lights will struggle to work even with thte engine running.as for derestricting it it doesnt have any restricors fitted to it you could try trimming the main length off the exhaust baffle this can sometimes give the engine a bit more poke and a little bit more noise too
adam bike doctor, November 2006