nobody in their right mind would spend money to fix up a cheap $300 generic made toy
its engineered and designed to have a normal engine life of about 10 to 12 hours of running time, then the engine locks up, the engine metal melts down, cracks, deteriorates, then its junk, you can't buy parts for it and the way its assembled its almost impossible to tear down.
then when its junk and can't be fixed you wasted all that money you put into it
search ebay for ''thumpstar'' accessory's,lots of neon's on ebay...but you do realise if its worth £50 and you spend £200 on it its still only going to be worth £50.
sorry man mini bikes not really worth butting any money into they are short life throw a way bike is what kids ride a round the block on cant do much to it to go faster some where arouind 35 to 40 wil be about it as for paint or neons get whatever you want but heres some performance parts to pick from