3rd match against villain in a row. I have a pretty good feel for how he plays.

Villain has a loose preflop calling range, but he rarely raises preflop, limping some very strong hands (limps JJ but raises hands like A9s at similar blind levels, but he will likely 3-bet a hand like JJ and maybe TT). I've seen him make a few bad post flop plays but it's tough to put him on a hand because he limps so many.

He tends to donk bet paired flops with an unscary 3rd card, but I've never seen him lead top pair (he's hit top pair several times tonight and never played it like this on an unpaired board). I feel like he has a weaker pair and I don't think he has the Q. He could have a draw and he could possible have 99-TT. If he has a pair of 6s or a weaker 8, I expect him to bet all streets.

Do you raise this flop or do I call? If I go with my gut and feel like he has a smaller/weaker pair that he will bet with again on the turn (and possibly the river), should I be calling down or putting a raise in and risk building the pot in a tough situation?

Full Tilt Poker $22 + $1 Heads Up Sit & Go No Limit Hold'em Tournament - t15/t30 Blinds - 2 players
The Official 2+2 Hand Converter Powered By DeucesCracked.com

BB: t1455
Hero (BTN/SB): t1545

Pre Flop: (t45) Hero is BTN/SB with 8 A
Hero raises to t60, BB calls t30

Flop: (t120) 6 8 Q (2 players)
BB bets t90, Hero calls t90

Turn: (t300) 2 (2 players)
BB bets t210, Hero calls t210

River: (t720) 7 (2 players)
BB bets t540, Hero calls t540

I think given read (villain doesn't lead top pair) this is fine/standard.

I generally would hate calling that river against most opponents that I play, but with read I don't see another way to play it.

As for raising at any point, that's really dependent on his hand range. If 99 and TT are a big part of it, then I don't think so. Also I'm not sure how big of a pot you can play with A8 and still be ahead. I lean towards calling.

If you raise, it should be on the flop, and only if you've been raising his cbets and you have a pretty decent feeling for his ranges beyond this point. As played I lean towards a fold given your description of villain, but it's somewhat close.