When my generator is off, the gas from the tank slowly mixes with the oil, this might take a few days, the float in the carb seems to be fine..... i just don't get it

Float levels don't just go bad. But that said you pull the carb and turn it upside down and set the float to be level with the bottom of the carb (bottom with the carb upside down.) Most new stuff doesn't have an adjustment. They break fairly easily. Don't ask how I know.
As long as you have it apart, pull the float and hold it down in a cup of fairly hot water and see if it bubbles which would indicate a hole in the float which would let too much gas into the carb causing flooding.
Make sure you clean the needle valve and seat and the carb inside while you are at it.

you have a float control problem that is allowing the fuel tank to drain through the carby past the rings into the crankcase. when stationary. Check for faulty needle and seat operation To be on the safe side in future install an fuel tap in the line before the carby and turn off when not in use.

The problem is probably that the float valve is not sealing closed tightly enough. The amount of gas being delivered to the carburetor is regulated by a float in a bowl of gas. When the motor is running, it may be OK that the float valve doesn't seal completely, because you are using the gas a bit faster than the minimum leakage rate through that valve. But when you turn it off, the gas keeps coming (slowly, but it doesn't stop) so if floods the engine, filling the cylinder and leaking into the crankcase. You need to remove the bowl on the carb and clean the float valve so that it can seal closed. Also, it helps when you turn off the generator to close the gas valve (hopefully it has one) instead of turning it off with the kill switch. When you do shut off the gas it will continue to run for a minute or two until it uses up all of the gas in the bowl. This tends to be a problem with generators more than with lawn mowers for two reasons, The generator is not used as frequently, so the gas in the bowl tends to gum up and causes the float vale to not seal. And the gas tank is located a little higher above the carb on a generator than it is on a lawn mower - so the pressure is a little higher, making it more likely to seep past the float valve. good luck, Al K

It's almost certainly gummed up gas in the carburetor. Get some carb cleaner, and some spray instant start. Drain the gas from the tank and put a small amount of 50/50 carb cleaner and gas in the tank. Remove the air cleaner, open the choke, spray a little instant start into the carb and start it. It may fire just a couple of time. Keep the choke on to try to pull a bit of gas through the carb. You may have to do this a few times. Once you can tell some gas is flowing, open the choke slowly to keep it running until you use up the 50/50 mix. Then try a small amount of straight gas in the tank to be sure it works right, before you refill the tank. Make sure you use a stabilizing additive in any gas that you store for more than a month. good luck, Al K

This typically happens when the needle and float are stuck open. The fuel from the tank then runs through the carb and into the cyliners, down past the rngs and into the crackcase to mix with the oil.

You may have something stuck in the needle and seat or a dirty carb. If the unit has been setting a long time you may have varnish in the carb and you might need to replace the part.

Remove the float bowl nut and then the bowl of the carb will come off and you should be able to tell what you have.

I would suspect that the float is sticking. Checking will require removal of (in order): seat, tank, air filter box/backing plate, and finally, the float bowl at the bottom of the carb. Insure that the float is not flooded, and that the float needle is free of trash.

The gas is leaking from carb but in the motor not out.
You should check and repair the carb flow valve. The floating unit may be full and bent down.

If the odd substance was at the bottom of the float bowl it was water. If it were oil it would have mixed with the gas and you would not have seen it. Drain the carb into a cup to remove any additional water from the carb and petrol tank. When no more water comes from the tank you should be okay to start the bike. Clean air filter? Water gets into the tank via condensation in the tank.

Drain oil... it is full of gasoline due to a bad float pin and rubber gromet in your carb. When your float pin and gromet fail, gas just keeps flowing into your carburetor, eventually flooding your motor with gas and oil mix.