.50 stars NL, flopped straight... how to get to value town?

[freshbeats]

i only play one or two tables at a time, so i try to concern myself with making the best reads and extracting the most value. that said, i'm still working on the value part.

i don't have a read on the villain here - over 25 hands running 40/4, only thing i've seen him show down is a c/called flush draw that hit, potted the river with.

PokerStars No-Limit Hold'em, $0.50 BB (6 handed) Hand History Converter Tool from FlopTurnRiver.com (Format: 2+2 Forums)

CO ($20.20)
Hero ($74.55)
SB ($47.35)
Villain ($68.90)
UTG ($52.30)
MP ($9.75)

Preflop: Hero is Button with 5[img]/images/graemlins/diamond.gif[/img], 4[img]/images/graemlins/heart.gif[/img].
<font color="#666666">3 folds</font>, <font color="#CC3333">Hero raises to $1.75</font>, <font color="#666666">1 fold</font>, Villain calls $1.25.

Flop: ($3.75) 2[img]/images/graemlins/diamond.gif[/img], 3[img]/images/graemlins/heart.gif[/img], 6[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(2 players)</font>
BB checks, <font color="#CC3333">Hero bets $2</font>, <font color="#CC3333">Villian raises to $4</font>, Hero?

should i be raising here? he didn't play his first draw like this, so should i get it in and hope he calls with a minraised overpair/set?

what about calling and value betting through unpaired turn/rivers?

obv, not my standard play from the button, but switching it up also tends to help.