Onan Emerald Plus 4000 won't start

Hello! We've got a problem with our generator. Our RV is fairly new (to us), it's a 30-foot '95 Winnebago Adventurer, And the generator worked when we got it a couple months ago. We ran it once for upkeep, but then when I tried to start it this time, it wouldn't kick over.
I press the start button, it'll do one revolution, if that, and then click a bunch of times. It does that with and without the RV running. The battery was just replaced, so I know it has juice.
Any suggestions? Solenoid? Starter?
Thank you!