I was looking at doing that for mine. I was going to weld up a plate with legs indexed for the stacking cups on the top of the genny that would then have a hold down for the tank so it couldn't fall off the. Order a new cap from champion that would have the hose adapter securely fitted to the vent hole so a vapor lock was created. To keep the siphon running that you would help to get started with a few pumps of the bulb. There should be enough suction to keep it. I've run the genny with the vent closed and when it choked out due to vacuum when the vent is opened there is a very encouraging sucking sound. In my plan I was going to make a y hose to feed another of the same with 2 stacked and the tank on top I thin it might have needed to be staked out on uneven ground but the siphon effec would be even greater.
