how loose can you play on the flop?

[Osric]

I have no hand to use as an example, so I'll just lay out a scenario. My main question here is how close do you stick to pot odds when deciding when to call a flop raise.

Lets assume you are on the button with suited connectors. There are 8 SB in the pot and you flop an inside straight draw and nothing else (4 outs). The guy before you bets giving you 9-1 odds. You need 10-1 for your draw, but due to implied odds you can call this.

At what point would you not call it? If you are only getting 7-1 would you call? 6-1? I know it is a little hard to analyze this without specifics as far as how many people in the hand and your relative position, so maybe this isn't a great question. But I think I may be being a little too liberal on my flop calls and would like to know how other people go about analyzing this.