Fold this boat?

UTG is 42.5/4.17 over 120 hands and will play any hand with an ace.
CO is 31.84/9.5 over 179 hands.

I know I probably should have reraised the flop but I figured CO likely had an ace and that I could checkraise the turn and trap UTG.

I'm mainly looking for feedback on the river. Someone has the ace right?

Party Poker 5/10 Hold'em (6 max, 6 handed) converter

Preflop: Hero is MP with 7[img]/images/graemlins/heart.gif[/img], 7[img]/images/graemlins/club.gif[/img].
UTG calls, <font color="#CC3333">Hero raises</font>, CO calls, Button calls, <font color="#666666">2 folds</font>, UTG calls.

Flop: (9.40 SB) A[img]/images/graemlins/diamond.gif[/img], 7[img]/images/graemlins/spade.gif[/img], 4[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(4 players)</font>
UTG checks, <font color="#CC3333">Hero bets</font>, <font color="#CC3333">CO raises</font>, Button folds, UTG calls, Hero calls.

Turn: (7.70 BB) 4[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(3 players)</font>
UTG checks, Hero checks, CO checks.

River: (7.70 BB) A[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(3 players)</font>
<font color="#CC3333">UTG bets</font>, Hero . . .

Final Pot: 8.70 BB