Now that it's running, and maybe you have a new battery (time'll ell on that one!) I suggest you do what I've learned the hard way to do:
1. Exercise that ONAN about Monthly. Apply as much load as you can.
2. Put Stabilizer in your Gas. I was having trouble with ours and coveted how another camper's ONAN was running. He told me he put StaBil in every drop of gas that went into that big 55 gallon RV tank. Long trip or not. I started doing that, and it's been wonderful. Switched to Starbrite's StarTron, which is far less expensive with equally good reviews.
I want my ONAN to serve when called upon, and I don't ever want to replace its Carburetor again.