Road Cycling - Loose headset/fork, how to fix? Just tighten screw at top of steerer tube?

Hi, I just received a new bike which was shipped to me. The headset/fork is loose. This means that the fork/wheel is wobbly.

The headset is a Chris King Nothreadset.

Is this a simple fix: do I simply tighten the nut at the top of the steerer tube to make the top and bottom of the headset until things tighten up?

Or is this a hard fix which means something ominous like my fork/steerer tube was cut incorrectly?

I'm hoping it's a simple fix. The bike had to be disassembled before shipment and although the fork was not removed before shipment, I'm thinking that the guy might have loosened it up a bit. It's a carbon fork though and I don't don't don't want to tighten any screws until I'm sure about what will happen!

Thanks,
MM

it's a simple fix. you have to completely loosen the stem bolts first, then tighten the top bolt, then retorque the stem bolts. when you tighten the top bolt, do it only a little, a quarter to half turn. then tighten the stem bolts up and check. continue until there's no more knocking or play. it's a little tedious but you don't want to overtorque the top bolt and ride with the headset too tight, it'll trash the bearings and effect your steering (in a bad way). just tighten it up enough to lose the play.

thanks bruce, you're my hero.

+1. And remember to have the steerer clamp bolts loose before touching the top bolt (as Bruce stated), otherwise you risk damaging your steerer by having your star nut or compression plug pop out or something while torquing down the top bolt.

Just to add, understand that when you're tightening the top bolt, you're just adjusting the load on the headset bearings; you're not tightening it down to hold everything together. The bolts on the stem actually hold things together; the top cap bolt is just preload.

That said, don't overtighten the stem bolts, particularly if you have a CF steerer tube. A torque wrench is your freind here.