opponet is fullring reg 16/13 (~22/18 for 6max) 4% 3bet (~6% 6max) flop/turn Cbet - 71/41
fairly common spot i guess in 3B pot with these types of pairs, on the turn when checked to..

1) Should we checkback, or bet the turn, when he checks the turn? WHY?
2) If we decided to bet, should we call now, or fold (or should i decide this on the turn when betting?) What should i look for? Why?

No-Limit Hold'em, $2.00 BB (9 handed) - Hold'em Manager Converter Tool from FlopTurnRiver.com

UTG+1 ($100.60)
MP1 ($218.05)
MP2 ($209.65)
MP3 ($310.70)
Hero (CO) ($230.55)
Button ($86.95)
SB ($126.60)
BB ($214.60)
UTG ($209.15)

Preflop: Hero is CO with 9, 9
5 folds, Hero bets $6, 2 folds, BB raises $18, Hero calls $14

Flop: ($41) 8, 3, 4 (2 players)
BB bets $23, Hero calls $23

Turn: ($87) 10 (2 players)
BB checks, Hero bets $42, BB raises $171.60 (All-In)