Can't get the stem on my Mongoose replica to go down. I've loosened the stem bolt, tapped the bolt, and loosened the headset, but no luck. Help needed.

are you sure it will go lower? the fork might have a double butted steertube? preventing you from lowering it.

I realize you're talkig about a replica Goose, but for the record, my 1984 Mongoose Californian won't take more than an inch or two of my DK stem. Won't go all the way down. Agree with the above comment about innerds of the fork perhaps precluding the stem going down further (even on a Mongoose stem).

Thanks. Ill stop driving myself crazy trying to lower the bars so my son can ride the bike.

In similiar cases (with double butted fork) i have grinded down the bottom edges of the stem wedge, usually helps.