got 03 yz 125 with pc pipe and just put in boyeson reeds . The jetting is stock for here in the uk will i need to change it. Anyone have experience with jetting here in the uk. how much does it differ to US. Whats the first thing to change and just how much room is there for error before seizure?
it should be pretty right with the added boyeson valve, those things make the bike a tad rich when i had it on my YZ125. as long as it seems to be running clean and youve done a couple of plug chops and everything is ok then leave it.