98 Vulcan 800 started last night wont start today getting fire seems like no gas, lines maybe froze?

More than likely you have a bad fuel petcock. No fuel should go from tank to carb without the engine running because the fuel is pulled by vacuum. Remove line from petcock an have it set to on or reserve position and if fuel comes out it is bad, and let's the fuel continue to flow to the carb and seep into the engine oil also. Mine was bad and had my oil thin as water with all the gas in it. Wonder it didn't wash a bearing out of the engine. Check and drain oil immediately if the petcock is bad.

If you change the exhaust pipes, you have to sync the carbs (if you cant sync them, you have to change the carb jets), usually it is backfiring because the carbs are not in balance.

if u tried starter fluid and it didnt at least hit or run for a sec or so then its not firing

If you live in a cold climate your gas line may be frozen or you may have water in your gas adding gas line antifreeze may help.

Sounds like you have either a bad fuel pump or a leak in the line somewhere. With a leak in the line it will take a long time for the gas to get up toward the engine. When it sits over night the gas line empties back into the tank and the process starts all over again

Sounds like the carb has not been cleaned properly, gas overflow like that could be caused from a worn seat/needle. Did you put after market exhaust on it?

Is your choke stuck open? And maybe the slides in the carb are stuck in the up position.

The line to drain the gas tank or carb? If you have auto shut off fuel valves(vacuum) set the fuel valve to "prime"(or check owners manual about fuel system)
Some bikes need a fully charged battery to start sometimes.
Will the bike fire on starting fluid?
Spark plugs OK?
Can you get a 1/4 " spark at the plug.
Contact me if you need more info.
Eric

could be the cam sensor. or crank sensor

check the fuel pressure sounds as if fuel pump quit