i am going to get a hotcam for my 400ex i know i can take it apart easily and put the new cam in but i don't know how to time it is there some kind of mark anywhere that will tell me if it is timed also do you have to mess with shims and other things when putting in a hot cam it says they are drop in

 

you need to remove the two allen head caps from the left side of the case cover. i think one you use a 10mm and the other maybe a 5 or so. that is just a guess. then you will want to rotate the 17mm nut behind the larger cap you just removed. you need to be looking where you removed the other hole while turning this. you will be seeing the flywheel. rotate slowly and align the "T" up on the flywheel. this is at top dead center. i would just go get a service manual. it takes you step by step. nothing else needs to be changed when putting one of these cams in. you do need to set the valves at .005 intake and .006 exhaust instead of the stock settings though.