Results: 320 pot
Final Board: 8 J 4
MP2 mucked and lost (-80 net)
MP3 mucked and lost (-40 net)
Hero mucked 9 J and won 320 (240 net)
SB mucked and lost (-80 net)
BB mucked and lost (-40 net)
The iso is totally ok vs most players ip. Don't think you need to go as big as nonsimplesimon suggests. You still might just call, but this prizes you oftentimes in if SB or BB make an huge iso raise what i don't like.
On the flop raise as big as possible in order to have the most fold-equity/commitment. Please don't fold later on. You might even just jam otf.