I am currently setting up my breaker box to be powered up in the event of a power loss to my home. I live "out in the sticks" and have been caught once with no power and watched as my basement was beginning to fill with water due to a intense rain storm that passed through the area. I found someone with a generator just in time before any major water damage happened but, it was a lesson that won't be forgotten. Since then I have acquired a 4000 watt generator which pushes 33.3 amps. I have run a 20 amp receptacle directly off my breaker box using 10 gauge wire. This is attached to a 30 amp breaker. I understand that the plug's rating itself is less than the breaker maximum but acquiring a 30 amp plug wasn't possible unless I went to a twist and lock set up. My generator will not accept this type of male plug. The run from my generator to my breaker plug is approximately 67'. Is it a terribly bad idea to buy a 75' 12 gauge extension chord and expect it to run the bare minimum's in the event of another power loss? I don't want to damage my possessions because of a lack of required power for optimum performance. Any pointers would be greatly appreciated.

#12 cord is good for 25 amps, with only two current carrying conductors, which is what you have.

The other issue is the distance. 25 Amps at 120 volts at 75 feet will produce voltage drop, and that may damage an appliance.

We need to know more about the load amps and voltage being used.

You will be better off using #10 wire.