650 will not start

What I have done so far: I always had to run with my choke on a little just to get it to idle. I swapped tanks and side covers with the parts bike. I turned up the thumb screw so it would idle about 1000 rpm I then ran it around for a while but it wouldn’t idle down below 3000 in between shifts. I knew I had carburetor problems so I thought I would ride it to work on Saturday and clean up the carburetor and lube the cable. Well it wouldn’t start, it was cold out and I ran down the battery. It did start for about 2 seconds then wouldn’t hit for anything. I had yesterday off so I pulled the carburetor off the parts bike went thru it completely. It’s so clean you could eat off it. I changed out the petcock and hoses. Tried to start, again ran for 2 seconds. The battery was low, so I charged the battery. Cranked it and again ran for about 4 seconds cranked again ran for about 2 seconds. Now again it won’t hit at all. I checked the plugs and they are firing, at least the one I checked and it didn’t look to bad. I guess I will try new ones. I am really at a loss as what to do next. Please any help would be appreciated.
Thanks
Marty

 

It won't start unless the mixture is correct or slightly rich and choke has to be working if it's cold. Make sure the jets are right size and in the correct locations, float level is correct and butterfly valves will close all the way and throttle cable is not sticking. Also, starter jets in float bowl bottoms should be clean or choke won't work. Then it should fire if you have a spark and compression.