I have purchased a 1816 b and I know it has to be warmed up pretty good to operate correctly, that having been said ,I read that it take 10-40 motor oil. I would like change the hydraulic filter and hydraulic oil in the event that there might be something else in there. Is there a proper way to do this besides changing the filter and draining the tanks or do I have to drain lines and hydraulic motors and cylinders. My problem is that when I engage the belt tensioning lever it will almost kill the engine and take right off either forward or backward , there is such a small amount of movement in the levers that it is very hard to keep it from going in either direction or stop moving at all. I don't think I could get any work done with it like that. Any tips or help would be greatly appreciated. Thanks PS. and it moves very fast when only at 1/2 to 3/4 throttle. You can't sneek up on anything the way it is.