Motorcycle Repair: My 2006 Honda Shadow Spirit 750 is backfiring alot., honda shadow spirit, spark plug gap

Question
I bought a 2006 Honda Shadow Spirit 750 a few months ago, and when I first bought it, it was running great.
I rode it to work one day, and got caught in a heavy downpour. At the same time, I ran out of gas on the highway, and switched over to the reserve.
I forgot to switch it back from the reserve.
It then sat for about 2 weeks before I tried to start it again, because in Florida, it was the rainy season, and it was raining almost every day.
When I attempted to start it, it would not start. I actually killed the battery. I bought a trickle charger, and recharged the battery. With a full charge on the battery, I was finally able to start the bike, but it would just barely start, and kept sputtering, as if it had water in the lines. If I tried to give it any gas at all, it would simply die. I ran it like this for quite awhile in my garage, trying to get the water out of the lines. Finally, after much time, the bike started to accelerate, although it was backfiring ALOT. I was able to get it to a point where I could ride it down the road, but again, with alot of backfiring. I used several different gas additives to dry out the gas, and to recondition the valves and gaskets, etc. I still have not ridden the bike since this last run down the road. I tried to start it again just a few days ago, and again, it acted like there was water in the lines. I managed to get it started, and managed to ride it down the road again, but this time, it appeared as if there was a loss of power, and I was afraid if I stopped, it would die. Still alot of backfiring. I do not have the owners manual, or a repair manual at this point, but wanted to simply change plugs, in case they got overly fouled through all of this "playing". But, I need to know what the spark plug gap should be set to, and I have not been able to find that info online at this point. Any help, advice, etc. would be greatly appreciated.

Answer
A common problem with rain is that if the ignition wires are a little cracked, water can short them out very easily. This would result is misfires and backfiring.

On the other hand, if the bike is completely dry, this shouldn't be a problem.

Also a bike which has sat for 2 weeks may need to have the carbs primed before it will fire up. Look for a prime setting on the fuel tap.