Leaking float needle or float level set too high?

On my 1980 xj650rj Seca when i start the bike up and look down the carbs, I can see gas just kinda shooting up through the main jet that the needle goes down into. I assume this isn't normal? I've tried to find other threads on this but I haven't found any with this same issue. The air filters usually smell of gas but, they don't seem to leak when the bike isn't running. The petcock is gravity fed, and I always turn it off after riding. Any help is seriously appreciated!

 

Also this is when it's at idle. When revving you can see some fuel mist shoot back out of the carbs.

 

DO NOT RUN THE BIKE ANYMORE!!!!

I think you'll find that you also have gas in the crankcase.
This is not an uncommon problem on carburated motorcycles that have not been maintained properly or have been allowed to sit for a long while.

Floats can stick.
Float needles do wear/ harden.
Float seat orings/washers can age and fail.

All need attended to before you ruin the engine, or have a fire.

IN THE CHURCH OF CLEAN

Replacing your Hitachi throttle shaft seals

Setting the fuel levels

Inside your Carbs

It sounds like you have an aftermarlet petcock, which is fine. Keep in mind however that there are rubber seals inside petcocks, and they also fail with age/neglect.
Turning the petcock off does not guarentee that fuel won't flow unless those seals are in serviceable condition.

 

I've been keeping a close eye on the oil level and to my surprise (and I assume yours as well), it hasn't gone up even a mm. I mean I'm sure there's some in there obviously, but not an extraordinary amount. When picked it up the PO had rebuilt the carbs somewhat and also forgot to put in the springs that push the vacuum slides back down. I completely tore them apart and soaked them, but I did use their parts that were already in there (which I probably shouldn't of). The petcock IS aftermarket, but it's brand new and I made sure the flow stops when it's off before I stuck it on. Would you say I need a new rebuild kit? Or just the seals/o-rings? Thanks.

 

I would say that you need to assume that the PO did everything wrong.
Tear the carbs down and assess. It may be that the floats are set too high, but are otherwise controlling fuel appropriately.

New kits are not a must, but if you are unsure of the correctness and condition of the parts a proper kit (not from an E-Bay seller) would be a wise investment.