i've recently bought an 03 crf 450, bone stock. i hate the ugly pipe on it and want to but an aftermarket one on it i already bought the power core 4 and was wondering if it's a good pipe for the bike. and is it worth it to do a header swap on these bikes the stock one lookes pretty good as apposed to size and bends. what are other good noticable mods for this bike??? mostly hillclimber(purpose of the bike) and also are these bikes jetted rich or did the idiot run too much oil on the filter i pulled the plug and it was black.