A preflop jungle - Spew/Genius/Meh?

[Astyanax]

£80 tourney at the gutshot and I am labelled the tourney donk because I raised with J2 suited got a free river after betting the turn and won with Jacks up. We're about 4 levels in and having been up to 4500 from 3500, I'm now back to starting stack.

Now to the hand...

I limp utg with 77 with blinds at 75/150. I chose to do this with the intention of just calling a raise not to reraise as I felt I had a pretty good feel of the table and was happy to play a medium pot oop. SB raises to 500 (psb).

A shorty who is playing 1250 moves all in. He is looking to get it in with any two - trust me.

I shove. Oh and btw the SB hasn't played a hand in 20 mins.

I know preflop has only a certain number of combinations with pps but I just would like some opinions on equity, ranges and general [censored].

Thnx and keep crushing! [img]/images/graemlins/laugh.gif[/img]