Mysterious bike problems (won't start, random misfire)
So here's alittle detail about the bike it's a 2007, bought it use to start right up and die right after. Adjusted the idle to 4000 and after awhile it will drop down and die. I'm not quite sure if I adjusted the cold idle right, but the bike stays on just fine if I keep giving it gas by throttle. But once I let go, it will shut off. Then some mysterious times, it will stay on and run just fine and ride fine until I shut it off and try to start it back up and it will get pissy and shut off.
Then another day comes, I try to start the bike and it will just keep cranking and won't start. So I'm pissed off and I step away for 30 minutes, try to start again and it will start but a loud bang from the exhaust from flooding I guess. And shuts right off after it starts. I watch and I can see the little oval moving where the throttle body cables are and they move just fine.
I tried switching out the tip over sensor, ecu, spark plugs, air box, gas tanks, fuel lines, rectifier. I tried fresh fuel, fuel cleaner, and etc.
I sprayed starter fluid directly into the throttle body and it won't start.
Also when it did finally hold a idle, a continuous extra "poof" will happen like a very mild backfire.
The bike is completely stock no modifications done to it. My friend just stopped riding it for 6 months and let it sit and came back one day and it won't start.
If anyone here can offer some kind of help please feel free to give me some input.