I didn't improve but the pot is large....call the river??

[Lmn55d]

OK, when this guy raised the turn I thought I was probably behind, but if he didn't have the straight, I probably had 4-7 outs (7 if he had something like 9Q, so I called. Now the river comes and I don't improve...is it worth calling?
Party Poker 5/10 Hold'em (6 max, 6 handed) converter (http://www.selachian.com/tools/bisonconverter/hhconverter.cgi)

Preflop: Hero is UTG with K/images/graemlins/spade.gif, A/images/graemlins/spade.gif.
<font color="#CC3333">Hero raises</font>, <font color="#666666">1 fold</font>, CO calls, Button calls, <font color="#666666">1 fold</font>, BB calls.

Flop: (8.40 SB) 4/images/graemlins/diamond.gif, Q/images/graemlins/spade.gif, K/images/graemlins/club.gif <font color="#0000FF">(4 players)</font>
BB checks, <font color="#CC3333">Hero bets</font>, CO calls, <font color="#CC3333">Button raises</font>, BB folds, <font color="#CC3333">Hero 3-bets</font>, CO calls, <font color="#CC3333">Button caps</font>, Hero calls, CO calls.

Turn: (10.20 BB) 9/images/graemlins/club.gif <font color="#0000FF">(3 players)</font>
<font color="#CC3333">Hero bets</font>, <font color="#CC3333">CO raises</font>, Button folds, Hero calls.

River: (14.20 BB) 2/images/graemlins/club.gif <font color="#0000FF">(2 players)</font>
Hero checks, <font color="#CC3333">CO bets</font>, Hero calls.

Final Pot: 16.20 BB

[7ontheline]

I'd call this almost always unless I knew the CO was very straightforward and passive. I've seen a lot of waiting until the turn to C/R TP, even with a lousy kicker. Maybe I'm just not good enough to lay it down though. . .his calling preflop and then sudden postflop aggression probably means you're beat. Big pot though. I wouldn't be surprised to see either KQ or JT here - maybe 44 or 99?