Are you a quitter or are you a bettor???

[wontons]

2-5nl. This question is more to the theory of how to play these type of hands not so much this one hand. I'm sittign with about 400 in LP with 78off. 6 callers limp before me I come along..so does button, 8 of us to flop. Flop comes 4 6 7 rainbow. All check to me...I dont see anyone having a monster here so I lead out for 25....first mistake..should have made it 40 perhaps to see where the real hands are if any. I get button to call and early position. Turn comes Q checked to me...whats your play...I've created a somewhat large pot meaning if I bet again it would have to be around 90. Who bets here and who gives up and more importantly which is the correct move in general?