Take the battery out and take it to Auto Zone, Napa, BatteryMart or some similar place and have it tested. I suspect after being on a 1 amp charger for 18 hours and all you get is a brief oil and neutral light on, the battery is probably toast. I've hooked up darn near dead batteries to a 750 mA tender and it was brought back to life after about 10 hours.
If the battery tests good, then I suspect you might have missed cleaning one of the contacts for the cables or one of the relays/fuses.

 

@monkeyboy22 I'm guessing the battery is probably bad even though it was purchased by the previous owner only 3.5 months ago. The fact that the indicator lights on the charger aren't fulling going to charged and just staying on "charging" makes me think its just the battery. I will take it to AAP (or get a multi meter) to get it tested then get a new if necessary.

 

I took the battery to Batteries Plus today. They measured it at 3.4 so it might be past the point of no return. They are still going to see if they can get it charged back up but I'll probably be buying a new battery. Any recommendations?

 

Yuasa.

 

Duracell, 2 year warranty, just like the one you took out, sold right there at Batteries Plus.

 

Get a can of AeroKroil, and spray towards all bolt threads that you plan to remove at any time in the future. It's "The oil that creeps", so spray it soon and let it be soaking in (especially exhaust and anything below the water line). Apply a small amount of die electric grease to all electrical connections after cleaning. Remove any fuel and replace with fresh fuel prior to attempted starts. Brake pads/shoes will need replaced in the near future.
Have you got a manual yet?

 

@TheGrandPoohBah You will see in the next video I upload at the end of this week/early next week (if you decide to watch it), but I actually took the Duracell into Batteries Plus and they were able to recharge it completely! I was hoping they would replace it for free since it was just purchased in August (by the previous owner) but apparently the warranty doesn't transfer.

I downloaded the original owner's manual but haven't bought any others yet.

 

Great news.
We wish you well, and keep us informed.
I would WD 40 (Water Displacement) the heck out of the primary, since that is where you found the most water.
Use anti seize on lots of threads, especially the spark plugs and just about all you reassemble.
Good luck!

 

Hey. So did a bit more work and decided I want to see if this thing will crank up. The battery is fully charged (reading 12.7 on the multi meter) so not sure what the problem can be. Is it a bad relay?

 

I haven't been through all replies but is this the first go at turning the engine over?
Did you remove the spark plugs to see if any water is in the cylinders?
The noise sounds like the solenoid goes but the starter motor is jammed? Or engine is completely frozen.
If not a way to check this out is get the back wheel off the ground. Take out spark plugs. Get into highest gear. Turn back wheel if you can and see what happens.