First time boat owner…appreciate any help that can be provided. Honda BF40D 40 HP outboard. Serial #BBDJ1102976. Engine cranks but will not start. Here’s what I tried/verified.
1. Boat ran great six weeks ago
2. When leaving lake, fresh gas w/Marine Stabilizer was added to top off tank
3. Now, six weeks later…engine cranks but will not start…it doesn’t even sound like it wants to start (no sputtering or popping)
4. I have verified…new plugs installed and gapped to 6.5mm
5. When cranking gas gets into cylinders
6. Spark is good on all three plugs
7. Tested kill switch by verifying that there is no spark when key pulled. Reinstall safety key and there is spark to plugs
8. Water separator container is near empty (red ring at the bottom of canister)
9. I believe I have verified spark and fuel…went to check air and found that the throttle body flapper was in the CLOSED position. I could not budge the flapper to open all all…seems to be stuck in the closed position
10. Do throttle bodies fail in a closed position and could that be the issue?

I apologize for the overly lengthy post, but am trying to provide pertinent data for any that can help!

Thanks…