Crankcase full of Fuel?

Hello Guys,
Newbie here...I have an 82 Sabre V-45,Im restoring. Fired it up this morning and got an "oil" warning. Popped open the oil cap to do a visual on the level,and got a gusher of fuel/oil mix. Best I can figure ALL of the fuel from the tank wound up in the crankcase.I have drained it,and now wondering how this happened....Stuck float on one of the lower carbs perhaps?
Has anyone seen this,and if so what was it?
Really dont wanna pull the carb manifold off again unless I have to.
Thanks in advance for any help.

I think you guessed right. Float sticks, gas runs through carb into cylinder(s) down past rings into crankcase. How long was bike laid up?? may have lots of gum or tarnish in carbs. Clean carbs!

The bike wasnt ridden for about 4 years. Bought it cheap.I pulled the carb,s,and
Inspected them. Bowl,s were kinda nasty,but all in all they looked ok.
Figuring the way the lower carb,s are mounted,it seem,s to be the only way this can happen.
Just can,t see any other plausible answer.Thanks!

Its the only path to the crank for the gas to get there.

You can try and tap the float bowl with a screwdriver handle to unstick the float or get the float valve to seat...but after sitting 4 yrs the carbs gotta come off and a thorough cleaning needs to be done...I'd say you have jets gummed up too....good luck

Yeah....I did notice a suction line going to the fuel shut-off valve,was kinda hoping it was coming through it,but that line is so small,it would take a year for 2.5 gallons to drain down.....Now I know what I gotta do...Thanks!

If you have a vacuum operated petcock,you'll want to check that too,if working properly it won't let fuel through without the engine running...