ST Satellite, river trips decision

[ansky451]

satellite to the 500 WCOOP event. Villain hasnt done anything out of line so far, I don't have a better read though. Anyone else fold this river? (I call preflop with this junk because CO has shown himself to be a donkey, and I want to get involved with him.)

PokerStars No-Limit Hold'em Tourney, Big Blind is t30 (8 handed) converter

MP1 (t2260)
MP2 (t2590)
CO (t1700)
Button (t1480)
Hero (t1570)
BB (t1630)
UTG (t1720)
UTG+1 (t550)

Preflop: Hero is SB with K[img]/images/graemlins/heart.gif[/img], J[img]/images/graemlins/club.gif[/img].
<font color="#666666">4 folds</font>, <font color="#CC3333">CO raises to t60</font>, <font color="#666666">1 fold</font>, Hero calls t45, BB calls t30.

Flop: (t180) J[img]/images/graemlins/heart.gif[/img], 9[img]/images/graemlins/club.gif[/img], 4[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(3 players)</font>
Hero checks, BB checks, CO checks.

Turn: (t180) J[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(3 players)</font>
<font color="#CC3333">Hero bets t120</font>, BB calls t120, CO calls t120.

River: (t540) 7[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(3 players)</font>
<font color="#CC3333">Hero bets t300</font>, <font color="#CC3333">BB raises to t775</font>, Hero...