100NL AK hit TPTK OOP turn completes fd

[Pomtidom]

Villain is 49/5/2.3 over ~40 hands.

Party Poker No-Limit Hold'em, $ BB (6 handed) Hand History Converter Tool from FlopTurnRiver.com (Format: 2+2 Forums)

Hero ($107.96)
BB ($7.96)
UTG ($106.94)
MP ($16.06)
CO ($17.80)
Button ($163.80)

Preflop: Hero is SB with A[img]/images/graemlins/club.gif[/img], K[img]/images/graemlins/club.gif[/img]. Hero posts a blind of $0.50. CO posts a blind of $1.
UTG calls $1, <font color="#666666">1 fold</font>, CO (poster) checks, <font color="#666666">1 fold</font>, <font color="#CC3333">Hero (poster) raises to $4.5</font>, <font color="#666666">1 fold</font>, UTG calls $4, CO calls $4.

Flop: ($16) 3[img]/images/graemlins/spade.gif[/img], 8[img]/images/graemlins/spade.gif[/img], A[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(3 players)</font>
<font color="#CC3333">Hero bets $16</font>, UTG calls $16, CO folds.

Turn: ($48) 5[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(2 players)</font>
Hero ?

Should I lead here? I put him on an flushdraw on the flop, but checking looks weak... What if I lead and get raised?

I'm open to all suggestions. [img]/images/graemlins/smile.gif[/img]

Thanks!

[Pomtidom]

Any thoughts on this?