Your code reference is 250.32.
You can not tie the "Grounded" conductor to the equipment after the Service Disconnect. You must carry an equipment ground conductor with any feeders and keep the Grounded conductor (Neutral) and the equipment grounding conductor separated. If your generator is a SDS you must use a 3-pole transfer switch (assume single phase) and transfer the neutral.
By the way Welcome to the forum. With a name like George your okay.