To become less predictable, I have been trying to play my combo draws the same way I would play a set. Problem is, I continue to run into sets when I do this. I would really like some input on the hand below. I feel there is a strong chance that villian (no reads) has a set here. Even if I think he does have a set, I shouldn't fold this, should I?

Is this how I should play almost all of my combo draws?

PokerStars No-Limit Hold'em, $2 BB (8 handed) Hand History Converter Tool from FlopTurnRiver.com (Format: FlopTurnRiver)

CO ($162.55)
Hero ($199)
SB ($398.70)
BB ($82.70)
UTG ($261.45)
UTG+1 ($471.95)
MP1 ($125.15)
MP2 ($306.35)

Preflop: Hero is Button with 7, J.
1 fold, UTG+1 calls $2, MP1 calls $2, 1 fold, CO calls $2, Hero calls $2, 1 fold, BB checks.

Flop: ($11) 8, 9, 4 (5 players)
BB checks, UTG+1 checks, MP1 bets $11, CO calls $11, Hero raises to $40, BB folds, UTG+1 folds, MP1 raises to $123.15, CO folds, Hero ?????