So, one of my spare tractors is a 2004 t800 with a mbn c15. A couple weeks ago it broken an exhaust rocker, cyl 4. I got around finally to changing it, adjusted all valves and injectors etc. Now i started the truck and it runs rough and smokes grayish white. I am trying to see if I missed something or if something else is hurt. Now I have read that the valve bridges can get damaged from this, not sure. Any help is greatly appreciated. Thanks guys.