Is this bluff totally insane?

[octaveshift]

My draw didn't make it, so I decided to jam with the scary board. Was this totally out of line?

Party Poker No-Limit Hold'em Tourney, Big Blind is t150 (9 handed)

MP2 (t3500)
MP3 (t2170)
CO (t3690)
Button (t1905)
Hero (t2230)
BB (t5750)
UTG (t3285)
UTG+1 (t1680)
MP1 (t5790)

Preflop: Hero is SB with K[img]/images/graemlins/club.gif[/img], 4[img]/images/graemlins/spade.gif[/img].
UTG calls t150, <font color="#666666">3 folds</font>, MP3 calls t150, <font color="#666666">1 fold</font>, Button calls t150, Hero completes, BB checks.

Flop: (t750) 5[img]/images/graemlins/spade.gif[/img], 2[img]/images/graemlins/heart.gif[/img], 7[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(5 players)</font>
Hero checks, BB checks, UTG checks, MP3 checks, Button checks.

Turn: (t750) A[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(5 players)</font>
<font color="#CC3333">Hero bets t150</font>, BB folds, UTG folds, <font color="#CC3333">MP3 raises to t300</font>, Button calls t300, Hero calls t150.

River: (t1650) 2[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(3 players)</font>
<font color="#CC3333">Hero bets t1780 (All-In)</font> Everyone else?????

Results will follow, if anyone cares.