Hello everyone, Thanks for your time.
I'm new here and I've searched the internet for hours on this issue but usually it turns out to be a bad battery or something simple. This is not the case here and it's driving me crazy.

2003 Deuce, Screamin eagle edition, 1550 fuel injected, 1200 miles, just purchased last month (sat for a years in climate controlled storage)
Randomly / Intermittently will not COLD start.
- No Check engine light or stored codes
- Does crank over, really well.
- Can hear the fuel pump run / shut off as it should once pressure is achived.
- Does have spark (checked by putting a spark plug on it and grounding, did not use a spark load tester, plugs look clean)
- Can smell fuel in the exhaust pipes when it cranks but doesn't start
- Backfires and Air filter backfires when it cranks but doesn't start
- Tried using starting fluid, still no start.
- New Key Fob battery
- New Battery - 1 month old
- Stays plugged into a battery tender
- Air filter is clean
- No vacuum leaks or fuel leaks
- Seafoam in the fuel seemed to help with this problem happen a little less often
- I live in Florida so outside temperature isn't an issue, somewhere between 70 and 80 degrees

Once it starts, it will not have an issue for the entire day. It will start every time after that until either the next day or sometimes several days later.
In the past, I've been out of town for 10 days... when i got back it started right up. The next day, no start.
Never has an issue out on a ride or stopping for gas etc. Just once in a while, refuses to start in the morning/afternoon.
Sometimes it takes 2 hours to start (try two or three times back-to-back then let it sit, then try again in 15-30 minutes) Randomly fires right up.

I've worked on all sorts of stuff for years and this one's got me stumped.
Any advice is appreciated. Thank you.