I need to change the rear shock on my bike if it is stock. The Question is since I bought the bike used, how do I identify that the shock is the original one that came with the bike which is suppose to be a 4.6. Second question, I want to change the fork oil in my bike and was wondering if there is a specific fork oil weight other then stock along with the fill amount that may help my front forks work better then the factory setting. My bike is a 99 WR400 and I weigh 200 lbs. ready to ride. I have read in the forum that my front forks are a bit harsh threw the center of the stroke and wanted to see what I could do to approve on this. Race Tech shows the front fork springs are set up for a 200lb rider so I should be good there.