Hi, I have a 2005 WR450. I would like to know please how often do I have to change the oil inside the front forks? I usually ride 70% on-road and 30% off-road. When I change the front forks oil, do I also need to change the oil seals or anything else at the same time? Another question that I have is regarding the clutch cover. I found out the other day that it has VERY VERY small cracks on it, on the flat surface near the Yamaha letters. When I ride the bike, oil comes out of the small cracks, but not even a drop of oil. Thus, I was thinking of using something like JB Weld to fix it. Do you think this is the best solution (other than buying a new cover)? Would it be better if I apply it outside the cover or should I remove the cover and use it on the inside? Would it hold properly on the flat surface? Thank you.