now dont get me wrong, im not trying to make you spend thousands of dollars, but your going to want a better exaughst. mine had a canister muffler, and it was so restrictive and baffled i couldnt get the max out of my motor. i picked up a straight pipe and got much better power, as for chain gaurds, it goes by the engine make, that ones a briggs, and as for fenders there not going to be cheap i dont think, so heres some links for you,