You can get gold-plated banana plugs in the proper size for generators from the people that sell Sinewave, too. It's a good idea, whichever you do, to stagger the plugs by a centimeter, or so, so you can't accidentally plug it into the wrong wire (or simply reverse the connectors on each wire).

I was going to suggest before you did, though, that you relieve the spade connectors a bit. They need to be snug, but not so tight that they are nigh impossible to remove; stick a slightly small flatblade screwdriver in the female connector, and wallow a bit (hold the connector with a pair of needlenose pliers, if you have to), and test the fit periodically.