Finally got my 400ex put back together. Stripped out one bolt on the valve cover (way before it even got close to the torque spec) but other than that it went ok. Starts and runs now (havent got a chance to ride, been putting wheel bearings in) , it smoked at first (replace valve guide seals) but cleared up right away. But I think I messed up on the exhaust gaskets? The top enbd rebuild kit came with two thick copper washers and I assumed those were it, but the heads had some carbon buildup or something very strong on the exhaust ports on the outside, maybe enough to keep it from sealing properly because now a lil bit of smoke comes out from the exhaust by the flange. Doesnt fly out, just looks like cigarette smoke. Did I use the wrong gaskets? Im sure it could change once I get it out and test drive it, just wanted to see what you guys thought first.