Ok, a buddy of mine lent me his bike to keep for a while as a 'buddy bike'. Its an '00 or '01 YZ426. I've used it maybe once taking out a friend in the last 6 months, was thinking of taking out another friend, so I thought I'd do some basic maintenance. Check the air filter... it began falling apart while being soaked in the no toil cleaning solution! Got a new air filter! Found out my '04 YZ250F oil filters will work, cool, I've got a bunch of those... got the 426 started, warmed it up, shut if off, found the bottom drain bolt, drained oil from frame and engine... WOW was it broken down and runny! Went to change the filter, and ran into trouble, and here is my question... do you REALLY have to take off the EXHAUST to change the oil filter on this bike?!?! The top bolt is blocked by the exhaust pipe, I can't see a way around it! I tried to loosen the bolts on the exhaust, and they didn't want to budge. So I got nervous, being that I really don't want to have to pay for having any bolts tapped out, and I stopped, filled it with new oil, and called it good (or at least better than before!) Anyone with one of these bikes have any suggestions, something obvious I might have missed? Also, I added 1.3 liters of oil. My 250F takes 1.1, and I know the older bigger bikes take a little more... anyone know how much exactly it takes? Thanks!