Adjusting valves on a 240D
 

I have read many of the posts on adjusting the valves, so think I will try mine since I just purchased it, and it does idle kind of rough. If I buy 2 14mm wrenches and bend them as some of the pictures I've seen, is that all I will need? What about the other big wrench that comes with the MB set if you purchase it, do I need that, or how can I make that? Also, any special feeler gauge I need to buy?(We dont have any around the farm,at least that are not all bent out of shape(lol)). I dont have a manual, but I think I can figure out how to do this by reading some of the posts on this subject in this forum.
thanks,
Jim