confused about KK hand

[Mariogs379]

PokerStars No-Limit Hold'em Tourney, Big Blind is t20 (9 handed) converter

UTG (t1680)
UTG+1 (t1510)
MP1 (t1320)
MP2 (t1400)
MP3 (t1530)
CO (t1470)
Button (t1550)
SB (t1540)
Hero (t1500)

Preflop: Hero is BB with K[img]/images/graemlins/diamond.gif[/img], K[img]/images/graemlins/spade.gif[/img].
<font color="#666666">2 folds</font>, MP1 calls t20, <font color="#666666">1 fold</font>, MP3 calls t20, <font color="#666666">3 folds</font>, <font color="#CC3333">Hero raises to t80</font>, MP1 calls t60, MP3 calls t60.

Flop: (t250) A[img]/images/graemlins/diamond.gif[/img], J[img]/images/graemlins/heart.gif[/img], 2[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(3 players)</font>
Hero checks, MP1 checks, MP3 checks.

Turn: (t250) 8[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(3 players)</font>
<font color="#CC3333">Hero bets t60</font>, MP1 calls t60, MP3 calls t60.

River: (t430) 3[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(3 players)</font>
<font color="#CC3333">Hero bets t140</font>, MP1 calls t140, MP3 folds.

Final Pot: t710

Results in white below: <font color="#FFFFFF">
Hero has Kd Ks (one pair, kings).
MP1 has 9c As (one pair, aces).
Outcome: MP1 wins t710. </font>

Maybe I should have raised to 100 preflop but i'm not convinced the caller would have folded his A9 if he called my raise to 80. with two others in the pot do you recommend check/folding this...I would have folded to a flop bet but it got checked around...should I have checked the turn?
ne ideas?
-Mario