how is this flop bet? Be brutal if needed. When should I be cont. betting with an overpair?

stacks are around 200. no reads, this is an 8-game table.

ShiFtYFiNGeR: posts small blind $1
Cold Fish: posts big blind $2
*** HOLE CARDS ***
Dealt to hoopla65 [7h Kh Ts Ks]
kamidawn216: folds
Flamarion: folds
hoopla65: raises $5 to $7
homecominkid: calls $7
ShiFtYFiNGeR: folds
Cold Fish: calls $5
*** FLOP *** [6c 4d Jd]
Cold Fish: checks
hoopla65: bets $20.90
omecominkid: folds
Cold Fish: challs $20.90

Heads up it would be okay to CB here. I think 3 way when the board has the opposite suits of your KKxx, it would be a good to time to give up...

against tight and passive players i would bet like 16 and expect to take it down a lot.

If not hand read and bet them off weak made hands on diamond turns and bet them off draws on blank turns