Just to add to all the other good advice, when your turning the engine over counterclockwise to line up your marks on the compression stroke, you normally have your spark plug out, and grounded, and put your finger over the threads, and you'll know for sure when your coming up on the right stroke, you'll feel the air pushing on your finger, (and how many of us here have had it almost right to your mark and blow right past it,lol? If you stopped on your mark and their was no play whatsoever in your arms, they you didn't adjust them on the compression stroke, and thats why they are clattering so badly. If all was done right,(on a completely cold engine I might add) I agree with shadetree, and your timing chain adjuster is at its limit, or stuck. If these tensioners are set up like my Suzuki engines (I don't own one) you can pull out the adjuster, and see if theirs any clicks left on the tensioner. You fully extend the foot on the tensioner, and place it back into opening, and if it bottoms out fully your chain is shot.
05 Suzuki DR650, Mikuni TM40 flatslide pumper carb,JE 10.5:1 piston,stage 2#190 Webcam,open airbox, Twin Air,full FMF system,Pingel fuel valve,Ricor Racing rear shock, Ricor Racing fork Intiminators, Progressive springs, Sargeant seat,DRZ250 tailight,custom plate,LED's,GPS,sumo fender,PT bars,Cycra brushguards IMS lowered pegs, aluminum skid,bearing chain roller,Pirelli,tank bag(gone)
06 Zuk KQ700, Kenda Bearclaw HTR radials Warn RT25 w/ syn. line, 1.5mm clutch shims