Gas valve shut off for engines when in storage?

OP here...

Thanks for all responses.

As said above additive best, gas OK, no gas bad.

MrOldman x2, except its my MH, no Corvette.

For the generator there is an electric fuel pump, just add a switch to turn off the pump, then run the generator until it dies.

WHY?? use fuel additive and forget it. I like sea foam it cleans the fuel system.

There will still be some fuel left in system. If you run engine out of fuel. With system now filled with a mix of air and fuel. Deterioration and gumming up will happen faster. Use a good fuel stabilizer. I have had good results with storing engine with stabilizer for over a year.

I store my Corvette for 6 months during the winter and I would add Gas Stabilizer in the gas tank then I would run the engine for 20-30 minutes. Just follow the directions on the bottle. Never had a problem come spring time. I also do this on my lawnmower, generator and snowblowers. Instead of taking out the battery on the Corvette I would put a trickle charger on the battery. If I was in your situation I would do the Stabilizer in both tanks.