oil is getting gas mixed in Help??

Okay I had my mazda motor rebuilt about six months ago. When We added 4.5 quarts of oil originally we never got a dipstick reading kinda weird. anyways it fired up and sounded good. well it has since sat pretty much while my garage is being built. a couple weeks back I started it up and I had a good sized oil spill coming from somewhere at the back of the motor, now last night I started it up and it appears I am leaking gas and oil mix and you can smell it a 1/2 block away what the hell is going on here and how do I fix ? I am running a stock carb and all emmissions crap till I get a weber, but for now I have to deal with this thanks for any replys.

I've had that problem on a chevy motor with a bad fuel pump. It was a manual one and the diaphram leaked into the crank case, it still ran fine though. I think the 87 still had a manual fuel pump. Just a idea.