I thought that I heard that on the 2001 426's it is'nt necessary to remove the head pipe to remove the oil filter. My bike still has the stock exhaust and I can't get to the top right bolt on the filter cover. Do i have to remove that freakin' head pipe every time I change my filter? Also, how often do I need to change or clean the oil filter? Another question, (I do'nt have an owners manual if you can't tell)when I fill my bike with oil after a change do i just fill it through the dipstick hole? It just makes me feel uneasy knowing that I did'nt put any oil in the case. Thanks for any help.