We didn't try the gen until a few days after we brought our RT home. It turned over but wouldn't catch. I did start the van's engine and then tried it again, and it fired up (Onan Microlite '02 RT 190P).
It's not a sprint(er) (unless you make it one), it's (hopefully) a marathon.
RV - 2018 Navion 24V + 2016 Wrangler JKU