Just wondering what all is involved, as the frame Im restoring had loose steering bearings and Im pretty sure the bearing races are prolly a little out of round. I did one on a Z50 yrs ago and it worked great.

Yes " i found the new tapered bearings too deep, i put a tapered on the bottom ,and new balls and race in the top, Then could fit the nut on,,,,

Me? I'd stick to originals. All races are still available from Yamaha and good quality ball bearings can be picked up from bicycle shops.

I have installed them on other Yamaha enduros, but not a DT2. Knock out the old ones and use the originals to pound in the new ones, being careful not to damage the new bearing surfaces. Pack the new bearing with grease. One advantage is you don't have to count the little bearings or chase them around the floor.

Almost every time I have replaced ball bearing type steering stem bearings with tapered ones the top and bottom triple trees are about an extra 1/8 to 3/16th inch apart. If you don't have extra space on the steering stem nuts then you might not want to use tapered rollers, like others have mentioned. I have added an additional o ring or rubber washers around the fork tubes on top of or below the headlight mounting ears to compensate for the extra distance between the top and bottom triple trees.

My experience is the same as JayB's. Tapered rollers will probably firm up the front end a bit, and may also wind up a bit cheaper than the standard cup and cone type.

I think "you pays yer money and makes yer choice".

I'm pretty sure the cones in my frame are welded in there, at least they appear to be

Post some photos if you can and the chaps here will comment on that! They'd have to be welded from inside the headstock......?