Don't give them credit for having a hand so often. Just like you, they only hit the flop one out of three (or four?) times.

I don't see why you'd wait for a big ace on the bubble. There's only four players left, so nearly any ace you pickup will most likely be the only ace dealt that round. Camping on those big aces and PPs when short-handed is a losing strategy. At least raise AX (ace-anything), K7+, and all PP. I'd recommend raising a few more hands, but AT LEAST do that.

I assume when you say "raise", you mean at least 2.5-3x the BB. Don't do this minimum raising crap - it gives the BB better than 3:1 odds to call, which justifies a call with nearly any two cards. Even if he calls with K2 and you have KT, he's a 3:1 underdog, but is being given 3.5:1 odds, so he's made the right call. Force them to make a mistake to call with those hands. By raising 2.5x the BB you give them 2.7:1 odds, which is just enough to make it a mistake to call with smaller aces and kings.

If you still have a decent stack size, you probably should AT LEAST call the minimum bet on the flop (and probably re-raise a large amount). I'll give an example:

Blinds are 100/200
Everyone has around t3000 chips
You're on the Button.

UTG folds. You pick up A4s and raise to 500 (2.5x the BB). SB folds and BB calls. There is now 1100 in the pot.

The flop comes 952 rainbow. BB minimum bets 100. There is now 1200 in the pot, and it costs you 100 to call. You certainly have 12:1 odds of calling here. You have a gutshot straight draw which will surely win it (4 outs), and both your hole cards may still be live (even though they technically give you 3 outs each you aren't sure if they will win it, so count these like 1 out each - for a total of 2 outs). You have 6 outs, which gives you about 7:1 odds of hitting your hand on the next card.

Still, I'd recommend often re-raising raggedy flops with ace-high against loose-passive players. You most likely have the best hand since most flops miss most people. The minimum bet they are doing is called a "probe-bet" or a "feeler bet". They're asking, "tell me a little something about your hand". Stick in a healthy raise to around 700 (slightly more than half the pot) and they will give up most of their hands.

Even when you raise to 700, with t3000 chips, you aren't crippling yourself. You'd be down to 2500 after the PF raise and then down to 1800 after the raise on the flop. 1800 chips is "okay" at 100/200 blinds. You have 9x the BB left.

Thanks alot for the reply
Usually when I raise preflop its 3-4x bb. I almost never minraise, not even when probe betting. It just looks so weak.
I'm going to try raising some of these weak bets as you suggest and see what happens. I suppose raising is only a good play on ragged flops? How do you extract the most money from passive players when you do hit?

If the flop is raggedy, uncoordinated, rainbow, and you hit TPTK with an ace or king, you could check the flop (or call the min-bet), then raise or re-raise the turn. The best players to do this against are the looser and more aggressive kinds, so I wouldn't do it too often against the loose-passive players.

Now if you hit something monstrous like trips or two-pair, I advocate slow-playing on most flops. But don't make it obvious. You have to show them you will check strong hands AND weak hands. If every other time you see a flop you throw out a continuation bet, and now you check, only the most unobservant opponent will bet into you.

I highly recommend reading Dan Harrington's Volume 1 and Volume 2 books on No Limit Tournament play. Volume 2 covers more of the late-game situations, but Volume 1 is still the best NL book out there.